SELECT 
  1 
FROM 
  tmall_lock_keys 
WHERE 
  key_id = 'db8a9e76b4835e4969e8d2403fa065d4f43112e1fd9f677d91bcb97cde66503f' 
  AND token = 'Iiklp+paWx6HXVGvbjCjU3QQ77vFhRM5dz49K8JosaY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.01476

JSON explain

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