The alternative to a loopcut in this case is to model as separate objects as is already proposed. This also applies to the planks of the door; they shouldn't be a part of the door, it's what the door is made of, thus they are sticked to it with nails or whatever. In case of modeling these as separate objects (the lock as well) the object will be constructed from parts:
Then all the planks and lock should get some nails in the corners for faking the reason why they still stay intact.
If faking some depth in the place where the lock is then it's possible to add some geometry there and extrude it inside. As the plank behind the lock is just a scaled cube, add 2 loopcuts, scale them appropriately and inset the resulting face. After that you can extrude that face inside and get a small indentation where lock can be put on:
Here the lock is moved by Y axis (movement is not confirmed hence the Axis line is shown as green) to show the indentation behind it. There's much less geometry to bevel for better effects of man-made objects and it can be operated much easier overall.