SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '16826e70d6daddd23a9a32379498a309f68756f248b8b5c95cc96aa2b530bfed' 
  AND token = 'CdhCdJLvSpuCVKSbfBIAc/TvsKm/YLif58LCgxuXAN8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00010

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}