Lambda Execution Function Issue For RDS Reboot

Greetings, I created a simple function taking as reference the basic Lambda in Python to start/stop RDS from here:

https://aws.amazon.com/es/blogs/database/schedule-amazon-rds-stop-and-start-using-aws-lambda/

But I changed it for reboot purposes, so my Python code is the following:

    # Lambda for RDS reboot given a REGION, KEY and VALUE
    import boto3
    import os
    import sys
    import time
    from datetime import datetime, timezone
    from time import gmtime, strftime

    # REGION: the rds region
    # KEY - VALUE: the KEY and VALUE from RDS tag
    def reboot_rds():
    region = os.environ["REGION"]
    key = os.environ["KEY"]
    value = os.environ["VALUE"]
    client = boto3.client("rds", region_name=region)
    response = client.describe_db_instances()
    v_readReplica = []
    for i in response["DBInstances"]:
        readReplica = i["ReadReplicaDBInstanceIdentifiers"]
    v_readReplica.extend(readReplica)

    for i in response["DBInstances"]:
        # Check if the RDS is Aurora
        if i["Engine"] not in ["aurora-mysql", "aurora-postgresql"]:
            # Check if RDS is a replica instance
            if (
                i["DBInstanceIdentifier"] not in v_readReplica
                and len(i["ReadReplicaDBInstanceIdentifiers"]) == 0
            ):
                arn = i["DBInstanceArn"]
                resp2 = client.list_tags_for_resource(ResourceName=arn)
    # Check tag
    if 0 == len(resp2["TagList"]):
        print("Instance {0} tag value is not correct".format(i["DBInstanceIdentifier"]))
    else:
        for tag in resp2["TagList"]:
            # if tag values match
            if tag["Key"] == key and tag["Value"] == value:
                if i["DBInstanceStatus"] == "available":
                    client.reboot_db_instance(
                        DBInstanceIdentifier=i["DBInstanceIdentifier"],
                        ForceFailover=False,
                    )
                    print("Rebooting RDS {0}".format(i["DBInstanceIdentifier"]))
                elif i["DBInstanceStatus"] == "rebooting":
                    print(
                        "Instance RDS {0} is already rebooting".format(
                            i["DBInstanceIdentifier"]
                        )
                    )
                elif i["DBInstanceStatus"] == "creating":
                    print(
                        "Instance RDS {0} is on creation, try later".format(
                            i["DBInstanceIdentifier"]
                        )
                    )
                elif i["DBInstanceStatus"] == "modifying":
                    print(
                        "Instance RDS {0} {0} is modifying, try later".format(
                            i["DBInstanceIdentifier"]
                        )
                    )
                elif i["DBInstanceStatus"] == "stopped":
                    print(
                        "Cannot reboot RDS {0} it is already stopped".format(
                            i["DBInstanceIdentifier"]
                        )
                    )
                elif i["DBInstanceStatus"] == "starting":
                    print(
                        "Instance RDS {0} is starting, try later".format(
                            i["DBInstanceIdentifier"]
                        )
                    )
                elif i["DBInstanceStatus"] == "stopping":
                    print(
                        "Instance RDS {0} is stopping, try later.".format(
                            i["DBInstanceIdentifier"]
                        )
                    )
                elif tag["Key"] != key and tag["Value"] != value:
                    print(
                        "Tag values {0} doesn't match".format(i["DBInstanceIdentifier"])
                    )
                elif len(tag["Key"]) == 0 or len(tag["Value"]) == 0:
                    print("Error {0}".format(i["DBInstanceIdentifier"]))
                else:
                    print(
                        "Instance RDS {0} is on a different state, check the RDS monitor for more info".format(
                            i["DBInstanceIdentifier"]
                        )
                    )
    def lambda_handler(event, context):
         reboot_rds()

My environment variables:

And finally my event named 'Test'

{ "key1": "tmptest", "key2": "us-east-1e", "key3": "reboot" }

I checked the indentation of my code before execute it and its fine, but in execution of my test event I got the following output:

{ "errorMessage": "2022-01-14T14:50:22.245Z b8d0dc59-714d-4543-8651-b5a2532dfe8e Task timed out after 1.00 seconds" }

START RequestId: b8d0dc59-714d-4543-8651-b5a2532dfe8e Version: $LATEST
END RequestId: b8d0dc59-714d-4543-8651-b5a2532dfe8e
REPORT RequestId: b8d0dc59-714d-4543-8651-b5a2532dfe8e	
Duration: 1000.76 ms	
Billed Duration: 1000 ms	
Memory Size: 128 MB	
Max Memory Used: 65 MB	
Init Duration: 243.69 ms	
2022-01-14T14:50:22.245Z b8d0dc59-714d-4543-8651-b5a2532dfe8e Task timed out after 1.00 seconds

Also my test RDS has the correct tag values in order to get the reboot action but nothing, until now I cannot reboot my instance with my Lambda function.

Any clue what's wrong with my code?

Maybe some additional configuration issue or something in my code is not correct, I don't know. I'd appreciate if someone can give a hand with this.

UPDATE 2022/01/15

As suggestion of Brettski@AWS I increased the time from 1 second to 10 then I got the following error message:

{
  "errorMessage": "Could not connect to the endpoint URL: \"https://rds.us-east-1e.amazonaws.com/\"",
  "errorType": "EndpointConnectionError",
  "requestId": "b2bb3840-42a2-4220-84b4-642d17d7a9e6",
  "stackTrace": [
    "  File \"/var/task/lambda_function.py\", line 103, in lambda_handler\n    reboot_rds\n",
    "  File \"/var/task/lambda_function.py\", line 16, in reboot_rds\n    response = client.describe_db_instances()\n",
    "  File \"/var/runtime/botocore/client.py\", line 386, in _api_call\n    return self._make_api_call(operation_name, kwargs)\n",
    "  File \"/var/runtime/botocore/client.py\", line 691, in _make_api_call\n    http, parsed_response = self._make_request(\n",
    "  File \"/var/runtime/botocore/client.py\", line 711, in _make_request\n    return self._endpoint.make_request(operation_model, request_dict)\n",
    "  File \"/var/runtime/botocore/endpoint.py\", line 102, in make_request\n    return self._send_request(request_dict, operation_model)\n",
    "  File \"/var/runtime/botocore/endpoint.py\", line 136, in _send_request\n    while self._needs_retry(attempts, operation_model, request_dict,\n",
    "  File \"/var/runtime/botocore/endpoint.py\", line 253, in _needs_retry\n    responses = self._event_emitter.emit(\n",
    "  File \"/var/runtime/botocore/hooks.py\", line 357, in emit\n    return self._emitter.emit(aliased_event_name, **kwargs)\n",
    "  File \"/var/runtime/botocore/hooks.py\", line 228, in emit\n    return self._emit(event_name, kwargs)\n",
    "  File \"/var/runtime/botocore/hooks.py\", line 211, in _emit\n    response = handler(**kwargs)\n",
    "  File \"/var/runtime/botocore/retryhandler.py\", line 183, in __call__\n    if self._checker(attempts, response, caught_exception):\n",
    "  File \"/var/runtime/botocore/retryhandler.py\", line 250, in __call__\n    should_retry = self._should_retry(attempt_number, response,\n",
    "  File \"/var/runtime/botocore/retryhandler.py\", line 277, in _should_retry\n    return self._checker(attempt_number, response, caught_exception)\n",
    "  File \"/var/runtime/botocore/retryhandler.py\", line 316, in __call__\n    checker_response = checker(attempt_number, response,\n",
    "  File \"/var/runtime/botocore/retryhandler.py\", line 222, in __call__\n    return self._check_caught_exception(\n",
    "  File \"/var/runtime/botocore/retryhandler.py\", line 359, in _check_caught_exception\n    raise caught_exception\n",
    "  File \"/var/runtime/botocore/endpoint.py\", line 200, in _do_get_response\n    http_response = self._send(request)\n",
    "  File \"/var/runtime/botocore/endpoint.py\", line 269, in _send\n    return self.http_session.send(request)\n",
    "  File \"/var/runtime/botocore/httpsession.py\", line 373, in send\n    raise EndpointConnectionError(endpoint_url=request.url, error=e)\n"
  ]
}

It's strange because my VPC configuration is fine, it's the same VPC of my RDS, its zone and the same security group. What else have I to consider in order to make my code work properly?