What if you can't get your picks into the keyhole?
I saw a lock that had a tubular key, and an airlock-like mechanism between the place the actual keyhole and the opening for you to insert the key. You would insert the key, and then activate the airlock-like mechanism which would transport the key to the keyhole.
There was then a mechanism to rotate the thing that was holding the key so as to unlock the lock.
The actual keyhole in this lock was never exposed to the outside.
What if you can't get your picks into the keyhole?
I saw a lock that had a tubular key, and an airlock-like mechanism between the place the actual keyhole and the opening for you to insert the key. You would insert the key, and then activate the airlock-like mechanism which would transport the key to the keyhole.
There was then a mechanism to rotate the thing that was holding the key so as to unlock the lock.
The actual keyhole in this lock was never exposed to the outside.