Yes, one key should open all.
Zammy, how much did the dealer charge for a new key? My '89 needs new keys and I'd like the OEM look. A couple of years ago they wanted $45.00 to make a key for my 2000 4Runner. I went to an Ace Hardware and they made an aftermarket key for less than $5.00. Home Depot didn't have the blanks and they told me to go to Ace!