This query ran against the "application_discovery_service_database" database, unless qualified by the query.

The application_discovery_service_database is created as part of the AWS Application Discovery Service. And you can use Amazon Athena for the data exploration. Refer https://docs.aws.amazon.com/application-discovery/latest/userguide/working-with-data-athena.html

If that is not your intended database then you can select the correct database from the Left panel, or edit the SQL query and prefix the database name for your table.