SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'da466461bb742d4ff8268ed7567cfa84b9d61d2ad71091652eb9d08eda1ec150' 
  AND token = 'jTVVqXWAqda12h6mhi3UeIGugiwtTUhtt7yVkmN6An4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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