SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '0538d59491b377ce41e69e2d439a57015b17d25e2699b53c29f75ae3f5289844' 
  AND token = 'D3HVJPD+In1YXOImliZgxw4GXJapBdcw7SHFshwPzNI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00037

JSON explain

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