SELECT 
  cscart_products.* 
FROM 
  cscart_products 
WHERE 
  cscart_products.product_id IN (
    10650, 9789, 10547, 9796, 9874, 9875, 
    9879, 9887, 9941, 9942, 9943, 9944, 
    10744, 10745, 10746, 10739, 10740, 
    10741, 10742, 10734
  )

Query time 0.00189

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "table_name": "cscart_products",
      "access_type": "range",
      "possible_keys": ["PRIMARY"],
      "key": "PRIMARY",
      "key_length": "3",
      "used_key_parts": ["product_id"],
      "rows": 20,
      "filtered": 100,
      "index_condition": "cscart_products.product_id in (10650,9789,10547,9796,9874,9875,9879,9887,9941,9942,9943,9944,10744,10745,10746,10739,10740,10741,10742,10734)"
    }
  }
}