SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '47132f2e770bfbdb9f4fceee689069a757d43157331d66b215a9b93b166bac73' 
  AND token = 'M1L+LJwDgGkfAJOYiOm/wVoY2lwVihinVHApcFlcoBo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00014

JSON explain

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