Cox dragged the Magpies back into the contest with consecutive goals during the last quarter and celebrated the second in Crows defender Josh Worrell's face.
The confrontation sparked a fierce melee, with players from both sides rushing in to take part.
Keays was one of the first, reaching up from behind Cox and ripping away the 211cm ruckman's goggles.
The action drew a 'misconduct' charge from the AFL's match review officer, with Keays fined $1500.
It can be reduced to $1000 with an early guilty plea.
Earlier this season, North Melbourne captain Jy Simpkin was fined for taking St Kilda player Mattaes Phillipou's GPS unit out of his jumper and throwing it away.
And Collingwood defender Nathan Murphy was fined for pulling down the shorts of GWS forward Aaron Cadman.
Last year, Hawthorn's James Sicily was fined for tearing off Western Bulldogs forward Aaron Naughton's headband.
Cox has worn the prescription eyewear all season after being given approval by the AFL to do so.
They are worn to correct a vision problem caused five years ago when he was poked in the eye, sustaining damage to his retina.
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