Dungeon of darkness

When you woke up, you found yourself in the abandoned dungeon, you don't remember how did you got here and everything about your existance is gone from your mind.

All you know is that it is not a dream and you need to escape, there is a door right in front of you but unfortunately it is locked and the lock seems to be having a slot for a several keys that intended to be used one after one.

Also as you inspect the lock you start to feel like something is moving behind you, perhaps this place is not completely abandoned...