This assumes you have already configured the aws command line tool. If not, check out my article on Getting Started with the AWS CLI.

The aws kms list-keys command can be used to list your KMS keys. This will return both:

• AWS managed keys
• Customer managed keys

~]$ aws kms list-keys
{
    "Keys": [
        {
            "KeyId": "2b32ca5b-ccaf-493b-b95f-d780d8e65eda",
            "KeyArn": "arn:aws:kms:us-east-1:123456789012:key/2b32ca5b-ccaf-493b-b95f-d780d8e65eda"
        },
        {
            "KeyId": "6ad1f21e-efa1-4884-bba2-fa3fbd1110ec",
            "KeyArn": "arn:aws:kms:us-east-1:123456789012:key/6ad1f21e-efa1-4884-bba2-fa3fbd1110ec"
        },
        {
            "KeyId": "a8cd1fa6-a162-47ef-8cf9-a5cc95bc8cd7",
            "KeyArn": "arn:aws:kms:us-east-1:123456789012:key/a8cd1fa6-a162-47ef-8cf9-a5cc95bc8cd7"
        },
        {
            "KeyId": "cb5302aa-e14b-4ad1-9d4b-4794a64f0b65",
            "KeyArn": "arn:aws:kms:us-east-1:123456789012:key/cb5302aa-e14b-4ad1-9d4b-4794a64f0b65"
        },
        {
            "KeyId": "f0c9f7f5-1956-4b8d-bb2f-e0f9aa951309",
            "KeyArn": "arn:aws:kms:us-east-1:123456789012:key/f0c9f7f5-1956-4b8d-bb2f-e0f9aa951309"
        }
    ]
}

The aws kms schedule-key-deletion command can be used to schedule a customer managed key to be deleted, using the Amazon Resource Number (ARN) of the key. Pending window in days must be between 7 to 30 days.

~]$ aws kms schedule-key-deletion --key-id arn:aws:kms:us-east-1:123456789012:key/cb5302aa-e14b-4ad1-9d4b-4794a64f0b65 --pending-window-in-days 7
{
    "KeyId": "arn:aws:kms:us-east-1:123456789012:key/cb5302aa-e14b-4ad1-9d4b-4794a64f0b65",
    "DeletionDate": "2023-06-22T21:07:50.625000-05:00",
    "KeyState": "PendingDeletion",
    "PendingWindowInDays": 7
}