Ignition locked

Okay, first thing is to try a different key It could be the transponder is not being read by the ignition switch module. A second way to test this is to keep all keys away from the car and see if the steering locks. If it does and the key unlocks it, the transponder is being recognized. Next would be the ignition switch module itself has failed and the internal release is bad. For that you need a shop with a dealer level scan tool as these cars will generate a code if the ISM is faulty, plus depending on your VIN there were some faulty ISM's out there which would act this way.
I would say if a different key does not work you are looking at a failure in one of the six components of the system, most likely the ISM itself.