I have no idea if that's even possible. you can bruteforce the klicense or check with ps3tools. somewhere, there's a klicense database, but it would be illegal to post here. I think ps3tools might have one, but it might just add to a blank txt file that adds your own. however, there's one filled out with thousands of licenses, since bruteforcing would probably require one of those quantum computers or a super computer due to how many permutations there are.
edit: okay, it's in the scetool folder, called dev_klic.txt. it's filled out with over two-thousand of them, so yours may be in there.