Fastest hash for non-cryptographic uses?

I'm essentially preparing phrases to be put into the database, they may be malformed so I want to store a short hash of them instead (I will be simply comparing if they exist or not, so hash is ideal). I assume MD5 is fairly slow on 100,000+ requests so I wanted to know what would be the best method to hash the phrases, maybe rolling out my own hash function or using `hash('md4', '...'` would be faster in the end? I know MySQL has MD5(), so that would complement a bit of speed on the query end, but maybe there's further a faster hashing function in MySQL I don't know about that would work with PHP..