SELECT 
  cscart_products.* 
FROM 
  cscart_products 
WHERE 
  cscart_products.product_id IN (
    19799, 19678, 19546, 19811, 19545, 19809, 
    19810, 19815, 19814, 19812, 19813, 
    19558, 19673, 19557, 19850, 19851, 
    19847, 19846, 19845, 19848, 19849
  )

Query time 0.00098

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": 21,
      "filtered": 100,
      "index_condition": "cscart_products.product_id in (19799,19678,19546,19811,19545,19809,19810,19815,19814,19812,19813,19558,19673,19557,19850,19851,19847,19846,19845,19848,19849)"
    }
  }
}