key on
Advanced (C1)informal
To pick out one person or thing and pay extra attention to it.
"The defensive line was told to key on their star quarterback and not let him scramble."
Hear it in context

I 1v1'd Pilat In EVERY Game For $10,000!
BuckeFPS · 56:43
Low key on the left.

Blender Story: Complete 3D Modeling Course (Full 6.5-Hour Beginner Guide)
MiM-Repository · 33:30
The five key on the numpad

30 Minutes of Patriots Offensive Highlights (2020-2025)
NFL · 0:54
Brian: YOU KEY ON NUMBER ONE.

Is Flighty a Top 5 App of All Time?
WVFRM Podcast · 87:40
A key A key on a baseball cap.

This Car Was Left Broken for 3 Years After a DIY Fail
HumbleMechanic · 18:11
We're going to turn the key on.