Translation:I would like to pay.
In Korean, the formality of the sentence is much dictated by the verb ending. So by using ether the impartial or familiar speech level, i.e "하고 싶다" or "하고 싶어", you are saying "I want".
Using the polite levels 하고 싶어요 (friendly) or 하고 싶습니다 (business-like) is more akin to saying "I'd or I would like".
In a restaurant, it is perfectly fine to use expressions s.a.
~ 먹고 싶어요 = I'd like ~, or ~ 먹을래요 = I'll have ~
to order food.