What year is your car? you may have one of the ignitions that requires you to push the key in before shutting it off. Im not sure if that was ever standard for celicas but it seems like my 90 was something like that.
If you have an auto, make sure your park is fully engaged when you try to step out or it may lock it in.
If neither of these is the case try a different key, yours may be worn down or have a defect.
If none of that works it may be your actual ignition but that doesnt seem right.