SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '28e26af492ae29fbd143e87d5245064280ee09d067a8d11d6947a93383be2ef6' 
  AND token = 'Bba524BqUK1BqCsURYqLOlUCyL4BO6LwTrECBsiCaAU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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