SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '0a4fcdba5e43cabdc21160c940057faf6df16857609a62e0c2ce28e4773a543b' 
  AND token = 'ZGadio1xeJooV4uY277fNCtNUPkmc+ExlV9wf6lbu5I=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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