I do not believe that your '97 uses such a handshake system.

If your batteries are dead, you will likely have to synchronize the remote to the IRCL, which is a very easy procedure and is in the owner's manual. If that procedure fails, it means that your key is dead (or made for a different car, which isn't the case with yours).

Your key has a blade and you have a mechanical ignition cylinder. There may be a chip in your key which communicates with the computer to allow a start (or not), but that chip is not powered by the batteries in the key and if your key now starts the car, changing the batteries won't affect that.

Newer 210's do not use a blade for the ignition lock. It is all electronic. That's what you are worried about, needlessly.