SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'b085f8a5d746f8421741cbe39603df2ea0bff00d3c11de1368072d834745d7ca' 
  AND token = '8DQcGXJ4DWpJdbHVxEJz60qTOsmVE4+frQBztz1H7uI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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