I adapted one of the above answers from cdhowie as I could not get it to work. This seems to work for me. I suspect it's also possible to do this with the UNIX_TIMESTAMP function been used.
SELECT * FROM your_table
WHERE UNIX_TIMESTAMP(DateVisited) >= UNIX_TIMESTAMP(CAST(NOW() - INTERVAL 1 DAY AS DATE))
AND UNIX_TIMESTAMP(DateVisited) <= UNIX_TIMESTAMP(CAST(NOW() AS DATE));