Is there (this) a case in which salting is dispensable?
Passwords should use a password hashing function. Password hashing functions are different from basic cryptographic hashes, though they use cryptographic hashes as part of their construction. Password hashing functions must use salt. (Password hashing functions can also tune their time and/or memory usage, cryptographic hashes generally can't.) 

So for your case, you probably don't strictly need a password hashing function. More importantly you probably want to not store the nonce in the database at all.