SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'c8769fc3dac0b221c598147a1c6c36f752794069ceaa780f0b4907036b5f3c37' 
  AND token = 'ajibSp+YXjfwuQGFnC9pg6dISFvn9EEKFmKOxm8dKTw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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