Notwithstanding any other provision of law to the contrary, all zoning ordinances adopted by class A counties pursuant to Section 15-36-26 NMSA 1953 (being Laws 1961, Chapter 21, Section 1, as amended) are valid and enforceable as of their effective dates and as they may have been amended from time to time. Such ordinances may be amended according to their provisions and may be enforced with respect to areas of the county not within the boundaries of a municipality; provided that such ordinances must be in effect as of the effective date of this 1996 act and shall not have been superseded by any municipal ordinance or by any joint ordinance of a county and a municipality adopted pursuant to the provisions of Sections 3-21-2 through 3-21-4 N.M. Stat. Ann..