When you say “Wario Land Demo” in your title, are you talking about a Wario Land Not For Resale Demo Only Cart? If so, then the most common warranty sticker found on those carts looks like what’s picture in the second image below. The sticker on the cart you have pictured looks like it’s just a generic warranty sticker that could’ve been used in mom and pop shops / used video game store.
Oh I see, thanks for the info. Yes it’s the not for resale version. There wasn’t a lot of pictures of the back of the carts so I just had to double check