SELECT 
  1 
FROM 
  tmall_lock_keys 
WHERE 
  key_id = '1f7f180dc7d0915a9669dc55c52e6be2283be6ebd9641470a5f46e7f169358e2' 
  AND token = 'hBKhVh8KouicPKuyrvxw7XJnLEitP0JyEPuRfDrh+bY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00791

JSON explain

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