There’s currently a timed Mythic+ keystone exploit in Patch 10.1.5, allowing players to complete high keystones in under 10 minutes and even solo. Be warned as Blizzard will likely ban for this!
Raider.IO Patch 10.1.5 Leaderboard
If you head to Raider.IO’s timed leaderboard currently you’ll see some crazy things going on: many keys are being timed in 10 minutes or less and sometimes even solo. Be careful though, as it’s likely that Blizzard will ban for this kind of exploit.