protected $productCollectionFactory;


public function __construct(
        .....
        CustomMyModuleModelResourceModelProductCollectionFactory $productCollectionFactory,
        ...
    ) {
        $this->productCollectionFactory = $productCollectionFactory;
       ....
    }

   public function execute()
   {
    $collection = $this->productCollectionFactory->create()->load(1)->getData();
    var_dump($collection);
die();
    return $collection;
    }

SELECT `main_table`.* FROM `custom_mymodule` AS `main_table`
/home/magento2/Custom/MyModule/Controller/Product/products.php:68:
array (size=1)
  0 =>
    array (size=6)
      'id' => string '1' (length=1)
      'product_name' => string 'Moongoose' (length=30)
      'product_sku' => string 'Moo74' (length=3)