SELECT 
  1 
FROM 
  tmall_lock_keys 
WHERE 
  key_id = 'a7e9ed7dd8206ce343f9848a360321754419f5a63462b19e5dff9e9eec17f799' 
  AND token = 'w5/e9l2Djdk9eNNPovDX0QfQ4JJKnISkjIEbAr1zWT8=' 
  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"
    }
  }
}