Seems fine to me to use pixabay.com images to make meme NFTs. It states the images can be used for commercial use (selling NFTs of adapted images for MEME tokens). Once you alter the image to make a meme NFT it's no longer an exact copy. The hiveme.me NFT marketplace is neither a platform for stock images or wallpaper images. I don't see any conflict.
Thanks for asking. In a little while after I respond to a few other messages I will be asking you (@lolztoken) a similar question from my @holovision account about use of your LOLZ logo.