Suresh Kandoth explains ENCRYPTION_SCAN in a non-TDE scenario:
There are three types of operations that acquire lock with the resource_type of DATABASE and resource_subtype of ENCRYPTION_SCAN:
– Encryption scan performed during TDE enable/disable
– Bulk Allocations that happen as part of bcp/bulk insert/select-into/index operations, etc
– Sort spills that are done as part of sort operators in the query plan
These locks are taken to serialize operations like bulk allocations and sorts with encryption scan.
Read the whole thing. It looks like this isn’t by itself a significant issue, but it is interesting to see this lock type against a database without TDE.