SELECT 
  cscart_products.* 
FROM 
  cscart_products 
WHERE 
  cscart_products.product_id IN (
    1669, 1400, 1673, 403, 358, 1167, 708, 
    1177, 1195, 1208, 1178, 1849
  )

Query time 0.00091

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 (1669,1400,1673,403,358,1167,708,1177,1195,1208,1178,1849)"
    }
  }
}