Can't cleanup obsolete Customer managed keys in Key Management Service

No being able to view details, disable and/or schedule key deletion. Getting:

DescribeKey request failed AccessDeniedException - User: arn:aws:iam:::user/root is not authorized to perform: kms:DescribeKey on resource: arn:aws:kms:us-east-1::key/005aa284-c9a3-4b75-8eaa-de1ac998786d because no resource-based policy allows the kms:DescribeKey action

DisableKey request failed AccessDeniedException - User: arn:aws:iam:::user/root is not authorized to perform: kms:DisableKey on resource: arn:aws:kms:us-east-1::key/005aa284-c9a3-4b75-8eaa-de1ac998786d because no resource-based policy allows the kms:DisableKey action

AWS Support under "Account and billing" saying: This issue is beyond our scope on the Billing and Accounts team ... For additional technical help, you can engage our support engineers by posting to AWS re:Post ... You can also contact Premium (!?) Support.

Appreciate your advice.