SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0636ef29441b984c282a36ca27fc2e8f0631755ae0cb42c87b1042a42aa4cbf4' 
  AND token = 'eHbGI/bDIBO6VQgjTVe4SgegFrnbQjvXVczoGkjYpfQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

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