SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0109ddbfcb0861672a87d3f5bc53979a5523c33821bed9eb976ed2048ce7033f' 
  AND token = 'UNqg2dvMOJXjUonUttE8Q/YSQdlt14nlS5tQMntYF3s=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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