The Earliest Known Locks and Keys in Egypt and Mesopotamia

We don't actually know who invented the first lock and key, but evidence does stretch back at least towards pretty early in the first millennium b c e. The earliest known locks and keys attested in the archaeological record were mostly not metal. They were generally these wooden, large, sort of club sized keys. But they had the basic principle, which is that movement by a bolt prevented them from being locked shut. And in principle, ancient locks would have worked just like you were saying today's pin and tumbler locks.