age from / age to
$meta_query = array( 'relation' => 'AND', array( 'key' => 'age_from', 'value' => '$ageMin', 'compare' => '<=', ), array( 'key' => 'age_to', 'value' => '$ageMax', 'compare' => '>=', ), );
$meta_query = array( 'relation' => 'AND', array( 'key' => 'age_from', 'value' => '$ageMin', 'compare' => '<=', ), array( 'key' => 'age_to', 'value' => '$ageMax', 'compare' => '>=', ), );