SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f62da35ec124879c57f5c3457c98fdd056486c05553d0ed31ba0fe27e82625f5' 
  AND token = 'oVhLMeOKt9Mj8WBnszJ6IAuhuZNvFDAzPnHTPNiELJc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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