SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '1108d4f5b112ac26ca6d07556bcffe41c5068fafcdb4ca0ca5603e10533ce423' 
  AND token = 'M+tr7A8LTdiCVDjsj6JZytEyao0PPsT8rMmxZi5+rg4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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