Uhhm the lock picking actually has a method to it. Its not just press all the keys and hope it unlocks.
Lower right corner of the screen you see how many tumblers the lock has, 4 to 6 it seems so far. Pressing your movement keys, ie: Forward, Back, Strafe Right, Crouch, etc one at a time until the tumbler moves. Once you see it move hold down that key and the tumbler will cycle into place with the opening to the right side of the image. Rinse and repeat.
If you just jam the keys until it opens it is going to take you alot longer to open the locks.