SELECT 
  cscart_products.* 
FROM 
  cscart_products 
WHERE 
  cscart_products.product_id IN (
    8343, 8344, 8269, 8404, 8101, 8102, 17629, 
    8649, 7970, 8506, 7818, 7569, 8717, 
    8106, 8356, 7356, 7357, 7355, 8169, 
    7743, 7742
  )

Query time 0.00097

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 (8343,8344,8269,8404,8101,8102,17629,8649,7970,8506,7818,7569,8717,8106,8356,7356,7357,7355,8169,7743,7742)"
    }
  }
}