I see. Well, I've checked those three versions that I'm talking about and didn't find your country there (if the one on your profile is the right one). I know there could be more region locked versions, but I don't know how to search for it
Also, a friend of mine that also lives on the EU (although on a different country) gave me a game on steam once without any problems. Unfortunally I couldn't give a game back to him.
The problem is that this was directly on Steam, so I don't know if it works the same for keys

Anyway, I'll try to participate. If I win pr find something about it, I'll inform you if it is or not. Anyway, thanks for the chance pal :)
(Just to be clear, I'm not participating just for that. I also want to play Gotham Knights one day, although I've saw some people criticizing the game)