The domain extension should not matter. I have not heard or seen that is if a factor.
"Cards credit" is a weak match for a search on "credit cards". Pages CAN be found for reverse word order, but generally the correct word order and words that are close together are going to be found first before those that are reversed or separated, like "Good credit is is the cards for you.".
Since the proper usage is "credit cards", I don't think you will get too much of an advantage, but the keywords in a domain is a small factor anyway. I wouldn't expect much from the domain if it was just parked, but I could be wrong. But for a developed site I think it will help more than hurt overall.
If you optimize your site for variations of the phrase "credit cards", then you should do ok.