with the 4 runners...or Toyota in general, cant you just take the lock cylinder to a lock smith and have him reset the cylinder to the old key. That's what I did with an old Volvo, then when I got an old BMW 318ic on the bmw forum a guy even posted directions and part numbers to take a new cylinder and set to your old key, which I did, so no second keys
my 4runner lock is doing good right now, but if I get in that situation, that's what I will look into doing
and if I remember, there is a thread here on this forum someplace of a guy fixing his stuck lock cylinder by taking it apart, so I bet the pins can be set to whatever key you have
just thinking out loud