In a medium bowl, whisk the whole milk, sweetened condensed milk, heavy cream, salt and lime zest together until thoroughly combined.
Whisk in the lime juice and whisk until completely incorporated.
Pour the mixture into a large spouted measuring cup. Pour the mixture into the molds 1/3-1/2 way full.
Add 1 and 1/2 teaspoons of the graham cracker crumbs, pushing down gently to eliminate any air pockets.
Pour the rest of the key lime mixture into the molds, leaving about 1/2 inch at the top of the mold for the graham cracker crumbs.
Add more graham cracker crumbs to fill up the molds, pushing down on the crumbs gently to pack. Lightly tap the mold onto the counter to get rid of any air pockets.
Place the lid onto the mold and place the sticks into the pops. Place the pops into the freezer for at least 6 hours, preferably overnight.
Once the pops are frozen, melt together the chocolate with the coconut oil. Line a baking sheet with parchment paper.
Remove the pops from the mold and dip in the chocolate mixture. Place the pops on parchment paper after dipping. Sprinkle the pops with the graham cracker crumb mixture and place back in the freezer until serving.