SELECT 
  cscart_products.* 
FROM 
  cscart_products 
WHERE 
  cscart_products.product_id IN (
    12552, 12642, 12648, 12611, 12596, 12607, 
    12608, 12610, 12643, 12649, 12609, 
    12644, 12650, 12652, 12653, 12654
  )

Query time 0.00043

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": 16,
      "filtered": 100,
      "index_condition": "cscart_products.product_id in (12552,12642,12648,12611,12596,12607,12608,12610,12643,12649,12609,12644,12650,12652,12653,12654)"
    }
  }
}