§ 23. Age limitation on term of judicial office. No person shall hold the office of judge, justice or surrogate of any court, whether of record or not of record, except a justice of the peace of a town or police justice of a village, longer than until and including the last day of December next after he shall be seventy years of age, except that a judge or justice in office or elected or appointed to office at the effective date of this section, as to whom no provision limiting his right to hold office to the close of the year following his attaining the age of seventy years was applicable prior to the effective date of this section, may continue in office during the term for which he was elected or appointed.