SELECT 
  cscart_products.* 
FROM 
  cscart_products 
WHERE 
  cscart_products.product_id IN (
    10631, 10632, 10633, 10634, 10635, 10636, 
    10403, 10404, 10405, 15781, 10406, 
    10407, 10408, 10409, 10410, 10411, 
    10412, 12853, 12854, 12855
  )

Query time 0.00060

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 (10631,10632,10633,10634,10635,10636,10403,10404,10405,15781,10406,10407,10408,10409,10410,10411,10412,12853,12854,12855)"
    }
  }
}