Whats needed to be changed if I'm moving SSRS DBs from a prod env to a test one?

I’m a bit confused on how I move the reporting database (and the temp one) from prod to test. I know after moving DBs I need to export its encryption key, but I would like to not cause any report to be sent by mistake to prod clients. Is there a way to clean the subscription table for example, without breaking the reporting service?