Slow to load image of Mongo with PHP

I'm developing a system that uses Mysql as a database and Mongo BD for image storage. The problem is that the loading of the images is very slow. NOTE: I am using laravel 5.2.

Function that loads image:

$db = new Conection("imagens");

$image = $db->find((int) $id);

if ($image != null) {
    $imageFile = $image->getBytes();
    return response($imageFile)->header('Content-Type', $image->file['MIME']);
}
return 'Erro';

Conection Class:

    <?php

namespace App\Bigdata;

use \MongoDB;

class Conection {

    private  $c = null;

    public function __construct($database="images"){
        $this->c = new \MongoDB(new \MongoClient(), $database);
        $this->grifs = $this->c->getGridFS();
    }

    public function find($id){
        return $this->grifs->findOne(array("_id" => $id));
    }

    private function getMimeType( $filename ) {
        $realpath = realpath( $filename );
        if ( $realpath
            && function_exists( 'finfo_file' )
            && function_exists( 'finfo_open' )
            && defined( 'FILEINFO_MIME_TYPE' )
        ) {
            // Use the Fileinfo PECL extension (PHP 5.3+)
            return finfo_file( finfo_open( FILEINFO_MIME_TYPE ), $realpath );
        }
        if ( function_exists( 'mime_content_type' ) ) {
            // Deprecated in PHP 5.3
            return mime_content_type( $realpath );
        }
        return false;
    }

    public function saveFile($file, $id, $mime=null){
        try {
            $name = explode("/", $file);
            if (count($name) <= 1)
                $name = explode("\", $file);
            $name = $name[count($name) - 1];
            $this->grifs->storeFile($file, array("_id" => $id, "filename" => $name, "MIME" => ($mime == null ? $this->getMimeType($file) : $mime)));
        }catch (\MongoGridFSException $e){
            return false;
        }
        return true;
    }

    public function saveBytes($bytes, $name, $id, $mime){
        try {
            $this->grifs->storeBytes($bytes, array("_id" => $id, "filename" => $name, "MIME" => $mime));
        }catch (\MongoGridFSException $e){
            return false;
        }
        return true;
    }

    public function updateFile($file, $id, $mime=null){
        try {
            $this->grifs->remove(['_id'=> (int) $id]);
            $name = explode("/", $file);
            if (count($name) <= 1)
                $name = explode("\", $file);
            $name = $name[count($name) - 1];
            $this->grifs->storeFile($file, array("_id" => $id, "filename" => $name, "MIME" => ($mime == null ? $this->getMimeType($file) : $mime)));
        }catch (\MongoGridFSException $e){
            return false;
        }
        return true;
    }

}