Key won't turn when I try to start the car?

There really isn't anything that would stop the brake from moving. As far as the key, have you tried to lube the tumbler?

This happens when the ignition switch needs to be replaced. The brake pedal will seem hard when the engine is not running. Here is how to change the ignition switch out to help fix the problem. I would get a replacement from the dealer so they can program it for you before installation. Check out the images (below). Let us know if you need anything else.