The superintendent shall deliver the keys which unlock the operating mechanism and the registering counters or counter compartment of the voting machine to the chief manager not later than one hour before the time set for the opening of the polls and shall take his or her receipt therefor. The keys shall be enclosed in a sealed envelope on which shall be written or printed:
provided, however, that, if the type of voting machine used requires the simultaneous use of three keys to unlock the registering counters or counter compartment, only two of the said keys shall be enclosed in such sealed envelope, the third key being retained by the custodian or the superintendent.
OCGA § 21-2-329