SELECT 
  * 
FROM 
  cscart_mb_salvage_cases 
WHERE 
  auction_product_id IN (
    20781, 20782, 20783, 20784, 20785, 20786, 
    20787, 20788, 20789, 20790, 20791, 
    20792, 20793, 20794, 20795, 20796
  ) 
  OR sale_product_id IN (
    20781, 20782, 20783, 20784, 20785, 20786, 
    20787, 20788, 20789, 20790, 20791, 
    20792, 20793, 20794, 20795, 20796
  ) 
ORDER BY 
  updated_at DESC, 
  case_id DESC

Query time 0.00036

JSON explain

{
  "query_block": {
    "select_id": 1,
    "read_sorted_file": {
      "filesort": {
        "sort_key": "cscart_mb_salvage_cases.updated_at desc, cscart_mb_salvage_cases.case_id desc",
        "table": {
          "table_name": "cscart_mb_salvage_cases",
          "access_type": "ALL",
          "rows": 58,
          "filtered": 100,
          "attached_condition": "cscart_mb_salvage_cases.auction_product_id in (20781,20782,20783,20784,20785,20786,20787,20788,20789,20790,20791,20792,20793,20794,20795,20796) or cscart_mb_salvage_cases.sale_product_id in (20781,20782,20783,20784,20785,20786,20787,20788,20789,20790,20791,20792,20793,20794,20795,20796)"
        }
      }
    }
  }
}