The glovebox and cubby lock are matched to the door and ignition barrels but they only use some of the wafers - the lock body is shorter.
The key should only go about 2/3rds of the way into the barrel. I have 2 MX5s on the drive where the ignition key serves all locks for the car. It looks like you either have a new ignition barrel and door locks, or the glovebox and cubby have been changed at some point.
I don't think your car would have had an integrated immobiliser originally, so if the key has a pocket in it for a transponder, you've got an ignition barrel and door/boot lock set from a later car.