SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2a96b999872c8ba241d7238443894f2e87caa84142b8cefe34dfc15aa1077915' 
  AND token = 'pLaI4TJHtorlQNYzMHdaYOr6Gk0rBCurU0iCjM5jrh0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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