User lockout information is stored in pm_project_user_params. To unlock, just execute this:
DELETE FROM pm_project_user_params WHERE user_id=[your user] AND param_name_cd='LOCKEDOUT'
Obfuscated users are automatically locked out if they ever perform the same query more than a certain number of times. This defaults to 7 and can be configured by the edu.harvard.i2b2.crc.lockout.setfinderquery.count parameter in the hive_cell_params table. To allow a user to repeat the same query after the lockout number of attempts, you must delete the previous queries from the qt_query_master table.