SELECT 
  1 
FROM 
  tmall_lock_keys 
WHERE 
  key_id = '5311cf95c56ebe8ab06a34ac379d87f845c6afea82fc4bc120ae92daccb3f8fe' 
  AND token = 'sASKtgkgPLZfc90CeuCrM4QTvioDGqyeJbLVriS8EcY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00781

JSON explain

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