I hear a small clicking sound when im riding slowly (sometimes) Any idea what it could be? Below is a simplified list of conditions for the clicking sound to occur

Speed > 20 mph
Rpm > 4k
1st gear only
Clutch MUST be engaged in order to hear the sound
(ruling out the rock in the tire thought)

Treatments attempted:
Pressure cleaned chain/sprocket off and re-lubricated
Chain does not seem to have any rust in it at all and was replaced a year and a half ago along with front and rear sprockets

I feel like the pressure clean fixed the problem but i still hear it once in a blue moon..

Chain guard off center possibly?

yeah check the guard, i had a screw missing on mine which made it loose.