Check out this article I found on Yahoo... noticed the Ford key for the picture...
It's probably for graphics purposes. They don't use a key like that for keyless-drive vehicles. At least not with Mazda. You usually see a card about the size of a credit card, but a little thicker, as the key. And, in the key itself is a removal metal key for situations such as if the battery goes out and you still need to get inside somehow.