SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'abd80d52b990ab18834e97fc476b61ff3b04ab7419f1812e10ba02a183ddc635' 
  AND token = 'eRfiZfdpIvUus5r98zdsDP5b17p3dauxfd74dreTBco=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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