CREATE TABLE table_name_66 (apparent_magnitude INTEGER, ngc_number VARCHAR(255), object_type VARCHAR(255), constellation VARCHAR(255))
what is the lowest apparent magnitude when the object type is spiral galaxy, the constellation is leo minor and the ngc number is more than 3021?
    
SQL: SELECT MIN(apparent_magnitude) FROM table_name_66 WHERE object_type = "spiral galaxy" AND constellation = "leo minor" AND ngc_number > 3021