Locks on entries could be implementend in many different ways. Usualy locking rows or tables on Database Managment Systems like SQL is not the best way for frontend applications. In the web world we have one database user that is connected to the database, but different users in the application. Like wordpress we created a locking system that locks entries when a user opens it – further we lock it per session, so you cant overwrite your a row with one modal in each other. You also get the information which user has locked the entry.
You can set the locktime in the global settings. Administrators could release locks in the WonderfulRelations dashboard.