SELECT 
  1 
FROM 
  tmall_lock_keys 
WHERE 
  key_id = '8a4ca02cc43ea4d119b963afed7dfb1e8514c41da5b7243e66d0ff77acb0aab3' 
  AND token = 'kZCvVs/3MHyD7SsCvohUtux42vcIj4zwpSngzKtXq9E=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00775

JSON explain

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