SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '526da3a465f77aa72a495d1dba7f2534eafcc5d833e00563863d47f8fb82c264' 
  AND token = 'VpsoVsd5jsWMvGsuufVJCsrI4Z8mdGfO08wAPocGw/A=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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