SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8b8107b1eda9414c54a52e6a9a2baa07d3ccdc72ab53ef6b71307d9ee5b6b4f4' 
  AND token = 'gjyoCMWqy8r7f4hBodJzvfsEvFh/HoGbqdBrnpUcwi8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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