SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9641016057405c71992d7945624d6be36f58686faa9d1c535cd0525d726bbee1' 
  AND token = 'yHesAJTaFcpZ58PNctw74lN6Bvum9CB4QQkaXlP7yUk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}