Most probably region locked (RU)

If you got this key from the Russian site giving them away, they are locked to RU and can't be redeemed outside Russia.

If you've gotten the key from the Russian website today, it's region locked to only Russia. You would need to delete the giveaway and recreate it with the proper region locked tags. We will not be able to reroll the giveaway due to it being region locked.

It doesn't look like this game is even available via Steam to customers anywhere in Asia.