SELECT 
  cscart_products.* 
FROM 
  cscart_products 
WHERE 
  cscart_products.product_id IN (
    1629, 1630, 1631, 1632, 1626, 1633, 1634, 
    1635, 1636, 1637, 1638, 1639
  )

Query time 0.00046

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": 12,
      "filtered": 100,
      "index_condition": "cscart_products.product_id in (1629,1630,1631,1632,1626,1633,1634,1635,1636,1637,1638,1639)"
    }
  }
}