SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '891647df41903c5cc8412e9cdcbced8569a32eea57a54c764694d33d098cf979' 
  AND token = 'SWoxWCQSN3RX8M1gHM7gErqoas5okCFe8yHGXVL8QIo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00040

JSON explain

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