Charge Key Management Service but no key created

If you go to Cost Explorer: https://docs.aws.amazon.com/cost-management/latest/userguide/ce-getting-started.html and Filter By Service - Key Management Service and Group By Usage Type, what charges do you see? Key Management Service is a regional service so be sure to check for keys by region.

You can also contact AWS Support for more help with Billing questions: https://docs.aws.amazon.com/awsaccountbilling/latest/aboutv2/billing-get-answers.html#billing-support