Check to see if your brake lights work. If the brake light switch fails it is a key input to the shift lock control that prevents the transmission from coming out of park. On a lot of cars you can hear a clicking sound around the shift lever area when you press the brake pedal with the key on. One of the wires at the brake light switch should have power key on or a fuse or wiring issue is the problem, on pressing the brake pedal that power should be transferred to the other side of the brake light switch.