Hi,
AEM does not store login details.
For the housekeeping, you can identify the active users following criteria:
1. Get All users who have created page/assets after XYZ date
2. Get all the users who have modified page/assets after XYZ date
3. Get all the users who have activated/deactivated page/assets after XYZ date
You can fetch above using simple QueryBuilder or SQL2 queries.
Based on the results, you can deactivate unwanted users.