SELECT 
  1 
FROM 
  tmall_lock_keys 
WHERE 
  key_id = '38ac906fbd8eaaed546dadec593db5c08befa18a8a20150de25c64067f49463f' 
  AND token = 'IZ/HkkGUvcLtsFCKr+znX4xdwQCh1GBiSOi5FrF1BT0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00857

JSON explain

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