Each election official of Clay County shall receive the rate of the minimum wage for each hour, or fraction thereof, that the polls are open per day for the performance of his or her official duties. The county governing body of Clay County shall supplement the compensation already provided by the general law of the state with funds out of the county general fund sufficient to bring the compensation up to the amount provided for by this section; provided, however, in any municipal election in which the official serves, the supplement provided for herein shall be paid by the municipality in which such election is held.