SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '004f5b1c12b4090fb259424563b9cd2e9a48ad026a5093f1646d39d03cd64c21' 
  AND token = 'j/eSkqu3cqVjT6qsj+liBoNYmVDK10HTH16vBwAG//w=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00047

JSON explain

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