It's possible the cylinder is corroded up...
Try freeing up with
PB Blaster, then IF it works...lube it with silicone paste, Mobil 1 oil or
SuperLube...
Be careful NOT to force the key...which is either made of brass or aluminum...
On a Toyota, the new cylinder will come with new keys...which means another key. A good locksmith should be able to repin it to the original key...