You can get Raid key from beating  Tv raid map, bunker, or easier Bunker Raid. After Beating this raid you get 1 Upgraded raid key, that you can use to open upgraded raid crate. And also you can buy Upgraded Raid key for robux in shop.

Units you can get from Upgraded raid key:
54.25% - screw

30% -fuell cell

10% - reinforced plate

3% - buzzsaw

0.75% - orbital laser drone

0.75% - Hextech Arm

0.75% - Overcharged Blaster

0.5% - Energy Blade