Shortcut to keyframes

doing animation of the mouth now to match the audio, and Im using 3 keyframes to do this. the catch is it’s a lot of keyframe duplication, and each time it takes a lot of scrolling through the list of keyframes prior to each duplication step.
is there a way to assign a keyboard shortcuts to these three keyframes to speed up pasting to the timeline? Or at least one keyframe at a time? Or copy/paste keyframes?