I have a web application that stores hashed password reset tokens in a database table. The tokens are randomly generated 256-bit values. I'm currently using Python's passlib sha256_crypt function to hash the tokens which defaults to using 535000 rounds.
In order to speed up the hash computation, I'd like to decrease the number of rounds that the sha256_crypt function uses going forward. Passlib allows you to choose a rounds value between 1000 and 999999999, inclusive. Given that I'm hashing random 256-bit values, would it be safe for me to decrease the number of rounds to as low as 1000? Would there be any serious security trade-off from doing so?