SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5aa03da46652f8679af3c6b60ca3889f8a410b24adc3b80313aac74a4591c8d7' 
  AND token = '+dk/bEvAUdohOw7CpjvMZQjESXuG5V6fg9BBjaE+WFI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

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