> Putting the display to sleep easily by moving the mouse cursor in the corner is nice (I’d still prefer a keyboard shortcut), and can be enabled in the system preferences:
You can lock the screen with cmd+ctrl q.
Control–Shift–Power button* or Control–Shift–Media Eject : Put your displays to sleep.
Here are some other keyboard shortcuts: https://support.apple.com/en-us/HT201236