Here you go, I have videos of the tech Blue Key:

Yelloy Key: (I personally do a different setup for this key but this is far easier to pull off lol)

Other people can probably give you a better explanation and I'll try to get a video for ya but I'll give it a go.

So that tech is called a 'keybump' and basically when you collide with the terrain from certain angles and speeds the game thinks that you're inside the wall, which allows you to grab the key without lowering it. There are certain consistent setups that allow you to do it easily once you know how.