It's very likely that this will unlock naturally without any special effort, but for those who want to target it, the Easy Score Attack and Match Attack daily challenges often start off with a ton of wild tiles exposed, as many as 15 or even 20. Simply load one of these up, and start clicking your way around the board matching wilds without regard for any other tiles. This works out to 3 seconds per match, and with that many wilds, you should be able to easily click faster than 1 match per 3+ seconds.