SELECT 
  1 
FROM 
  tmall_lock_keys 
WHERE 
  key_id = '02e292eec6c82c5734a711e1512142dc2a2320800c7bac57ef58a180e817d42d' 
  AND token = '4SNxDnzMv5Z21e26pfdE6GJtJETWkQiGaWmXAaQNwWw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00779

JSON explain

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