On my '93 SHO the trunk key was also the door key and I think the glove box as well. The ignition key was by itself. Or maybe that was my '88 EXP and the '93 only had one key. Hmmm, I don't remember. But I do remember that from my experience, if your Ford has a squarish key and a round key, the squarish is ignition only and the round key works the other locks (door, glove box, and trunk/hatch).
-Rod