SELECT 
  cscart_products.* 
FROM 
  cscart_products 
WHERE 
  cscart_products.product_id IN (
    12616, 12599, 10666, 10664, 10663, 10661, 
    10659, 10658, 10657, 12619, 12620, 
    12593, 12595, 12585, 12587, 12623, 
    13091, 12588, 12590, 12591
  )

Query time 0.00129

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 (12616,12599,10666,10664,10663,10661,10659,10658,10657,12619,12620,12593,12595,12585,12587,12623,13091,12588,12590,12591)"
    }
  }
}