SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '73ebb90ea926b6416d23965f2d0a52ecdf0dfad0931b8900d2b9ff8403d46c15' 
  AND token = 'dQafVJbvyCYe3DJqGvpGaTJlaMjH0pwCIER+He6k18Q=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

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