SELECT 
  cscart_products.* 
FROM 
  cscart_products 
WHERE 
  cscart_products.product_id IN (
    2014, 2389, 2434, 1603, 2376, 2396, 779, 
    2466, 2232, 2354, 3119, 275
  )

Query time 0.00083

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 (2014,2389,2434,1603,2376,2396,779,2466,2232,2354,3119,275)"
    }
  }
}