Just let it dry...in near 20 years time, my garage has flooded twice, both times an inch or 2 of water above the few tiles that were not floating. Fun to walk on
I never did anything special, just let it dry out naturally and when I lifted up the floor to move to my new garage, the concrete was as clean as the day i put it down, no mold or mildew. I have solid Racedeck tiles, not the ones with the holes, I think those would have dried even quicker but those were not made when i got my tiles and I don't like them anyway, my shop sees a lot of woodwork and the sawdust would get below the tiles. Also last year, my shop has been a body shop, did a lot of body leading and lead shavings along with tons of bondo being sanded, again that would get under the tiles.