Driver's door stopped being able to unlock with the key so I had to use the passenger door. After a while, the lock in the passenger door gave out. So I would either have to leave it unlocked or climb through the rear hatch.

The mechanic said there was dirt/dust build-up preventing the pins in the lock to match the key resulting in the inability to use the key on the door. After having them replaced he said to every now and then to oil the key and insert it in the lock a few times.