SELECT 
  1 
FROM 
  tmall_lock_keys 
WHERE 
  key_id = 'a1634bf78806146ace8b0b82865ac45f2e7142c2dc154864558f211c8a36ae35' 
  AND token = 'faxIq0ZPfWoOCUiWQF3znkCspigRb9GT8uZgIajuaZw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00757

JSON explain

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