Once Spotlight shows Activity Monitor, hold Command + Return to open it in Finder (so you can pin it to the Dock).
This article covers every useful shortcut for Activity Monitor—from keyboard commands to hidden mouse tricks—so you can kill rogue processes, track memory hogs, and monitor energy usage without ever touching the trackpad. Before you can use any other shortcut, you need to launch Activity Monitor instantly. shortcut for activity monitor mac
Command + Option + Esc