Laravel find nearest location in km from lat, long database

gistfile1.txt

private function findNearestLocation(Request $request)
{
    $location = DB::table('locations')
        ->select('name', 'latitude', 'longitude', 'region', DB::raw(sprintf(
            '(6371 * acos(cos(radians(%1$.7f)) * cos(radians(latitude)) * cos(radians(longitude) - radians(%2$.7f)) + sin(radians(%1$.7f)) * sin(radians(latitude)))) AS distance',
            $request->input('latitude'),
            $request->input('longitude')
        )))
        ->having('distance', '<', 50)
        ->orderBy('distance', 'asc')
        ->get();

    return $location;
}