SELECT 
  cscart_products.* 
FROM 
  cscart_products 
WHERE 
  cscart_products.product_id IN (
    12628, 12602, 12640, 12647, 12588, 12605, 
    12606, 12637, 12612, 12613, 12641, 
    12554, 12552, 12642, 12648, 12611, 
    12596, 12607, 12608, 12610
  )

Query time 0.00051

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 (12628,12602,12640,12647,12588,12605,12606,12637,12612,12613,12641,12554,12552,12642,12648,12611,12596,12607,12608,12610)"
    }
  }
}