Then you're good to go! In a 5 gallon, one betta and one snail should really be the most you ever have. Adding live plants (if you don't have any already) is going to help with the water quality even more for that much bioload, especially because a snail's waste can be hard to see so usually you won't know to remove it until there's a heap of it everywhere – unless you use the vac for each water change.
Athena the Female Crowntail Betta
RIP Leo the Nerite Snail
Wishlist: Black Orchid CT
Tiger Nerite Snail