earlier coronado records

where can i find marriage records for a jose (aka joseph lorenzo )coronado and or maria margarita Segovia? still trying to find parents for them i had managed to find some records regarding their children as follows: balbina theordora maria severiana and or pedro coronado . all children were baptized near Santa Maria DE LA Asuncion, Santa Maria Del Rio, San Luis Potosi, Mexico. oldest child balbina was born 1765 so they had to be married around close to 1760's.