I don't think a general locksmith would be able to cut a key from the kawi keycode, but a kawi dealer certainly can. Good wiki entry for the older keys here:
http://faq.ninja250.org/wiki/EX250F_key_blanks
Hillbilly Cycles in West Virginia (
http://www.hillbillycycle.com/) used to be good for ordering keys if you had the keycode, but it's been a few years since I've needed one.