A door with a lock can only be opened by those with a key... as well as anyone that can pick the lock, jimmy the lock, remove the door from its hinges, remove

A door with a lock can only be opened by those with a key... as well as anyone that can pick the lock, jimmy the lock, remove the door from its hinges, remove the lock, break the door down, go under the door, go over the door, get somebody with a key to open the door, and many other methods which can be found with just a little imagination.