SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '95304799d8f29dbdb0f13f4db1d37047f2b32528498e715916240f125dfd46d1' 
  AND token = 'k9GaRVN//YQ4a2kjaOrZIgan7uJCV8e73LIDogLJ2VU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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