SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'e6231a74a9afaf88fca5bbf56989885f975aef1016e2cf98fb9d136b8fc12942' 
  AND token = '9QhuLaXY46NETXy93fWpBwawXF/zM1QLGvJIajqvUA8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

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