Right now, a fresh character with 10 stealth 10 int, 10 dex can pick a wooden lock on a timber house in well under a minute.
I think this could use a change. A character with 10 stats against a wooden lock should take at least 5-10 minutes to pick on a house, but a shorter time on other objects, like chests. Although not good, people may then start considering the prospect of using one.
The juice here isn't worth the squeeze otherwise. Imagine investing in the prospect of constantly carrying a key around with you. Losing one of your precious inventory slots for a 45 second delay in being robbed? Whats the point?