SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '02cdd577b7c796cdf835924ff6a537272741a500dcf55b9b40f246136d07d372' 
  AND token = 'lNOh5qRxNeJ6QpXUHFHP4dKbeQaVVVZuGgIN/u8ieXU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

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