SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2fadf38702d1f32e0d9ec02d5cb68daefe2ed55842358ef5c3810c35c36edc08' 
  AND token = 'sYUiU1ZrmzEBt8v/5+GUzfjTZ16MYpyktqL2TuMqYeU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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