As some may say, a lock is a lock is a lock. Were that lock to be installed in an otherwise impenetrable vault, then it would do much to persuade the common thief not to even try. But in a glass cabinet? If someone wants to get in, they'll simply break the glass and forgo trying to pick the lock.
I can't answer your question about lock sources. But I can offer that observation. Perhaps, if you already have a lock that isn't considered "high security", it may be sufficient to ward off those who wouldn't try anyway. But the one who really wants in...? He'll just break the glass.