On and after October 1, 1961, the right to elect to receive credit for service pursuant to Section 75030.5 shall apply only to a judge who has served as a judge as defined by Section 75002 for at least six years or who is elected to the office of judge as defined by Section 75002. This section shall not apply to any judge who is a member of this system on September 30, 1961, or to any person who, on or after January 1, 1986, first becomes or continues as an elected state constitutional officer, as defined by Section 75030.5, in a term which commences on or after January 1, 1986.