SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'bf8b95954e34f02a099096390f808123f42a83e003d3129aef85eb649ad11378' 
  AND token = 'YGXhssm9OkzCATi6tER7vpCvjNG6YtaXWt09Q9yyM9w=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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