Only select from db if datetime is less than 1 hour from current datetime?

PHP
2

I have come up with this, but still no luck… Any ideas?

$sql = "SELECT UNIX_TIMESTAMP(timetodraw) newtime, UNIX_TIMESTAMP() nowtime, game_id FROM ".$prefix."_games WHERE UNIX_TIMESTAMP(timetodraw) < UNIX_TIMESTAMP(3600)";

What I want is to only get records that are within one hour of the current time.