I haven't hatched Keets before, but found this:
"There really is no 'typical' hatch. Sometimes a keet will pip and zip in an hour. Others will pip then rest a few hours before they start zipping. Others will partially zip then rest. A keet can take up to 24 hours to hatch but I find that keets pop out of their eggs a whole lot faster than chicks do! "
Here:
https://www.muranochickenfarm.com/2019/05/how-to-hatch-guinea-keets.html
To me it sound like your little one might have pipped
not into the aircell, and is stuck. With chickens, I wouldn't expect a chick to still be alive after 3 days pipped. It's likely time to help, that is if you're willing to attempt assisting.
Here is an awesome resource for how to. There is a simplified one on BYC somewhere, but I don't seem to have it in my saved links.
https://www.backyardchickens.com/articles/step-by-step-guide-to-assisted-hatching.64660/
I would like to say that even if you choose to assist, the likelihood of this little one surviving is very low.