SELECT 
  1 
FROM 
  tmall_lock_keys 
WHERE 
  key_id = '9e8f1476ffde8f32210f17c30a41fa09c3264ac80a880c8fcb8ca7906488e06d' 
  AND token = 'avKOdiu8huxZ07VwmhAxVG9dm6CYkQSOmK6FTdMr3RU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00846

JSON explain

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