This is a basic attack combination from the mount.
The first key lock move is only intended to cause the opponent to try to stop it.
When the opponent reacts he leaves his other arm vulnerable.
It is considered Kuzushi because it is a combination attack and causes a reaction which is taken advantage of.
It is a higher level to switch to a different technique or perform a technique in order to cause a reaction to capitalize, than to simply try to muscle it forever.
kuzushi dojo 