key wont turn! goes in n out but just wont turn

just happened last night. parked the car, came out this morning and the car dings when u put the key in but it wont turn and the wheels not locked and ist in park. its an older convertable sebring

sounds like  a key cly stuck  smack tehkey when turing it at the same time

Spray wd40 into the lock cylinder and tap on the lock and turn your key at the same time. If this works you want to have the lock cylinder replaced.