SELECT 
  * 
FROM 
  cscart_mb_salvage_cases 
WHERE 
  auction_product_id IN (
    20845, 20846, 20847, 20848, 20849, 20850, 
    20851, 20852, 20853, 20854, 20855, 
    20856, 20857, 20858, 20859, 20860
  ) 
  OR sale_product_id IN (
    20845, 20846, 20847, 20848, 20849, 20850, 
    20851, 20852, 20853, 20854, 20855, 
    20856, 20857, 20858, 20859, 20860
  ) 
ORDER BY 
  updated_at DESC, 
  case_id DESC

Query time 0.00030

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": 56,
          "filtered": 100,
          "attached_condition": "cscart_mb_salvage_cases.auction_product_id in (20845,20846,20847,20848,20849,20850,20851,20852,20853,20854,20855,20856,20857,20858,20859,20860) or cscart_mb_salvage_cases.sale_product_id in (20845,20846,20847,20848,20849,20850,20851,20852,20853,20854,20855,20856,20857,20858,20859,20860)"
        }
      }
    }
  }
}