SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'cbca1b1420a3056071b441e966258287628d76f80cabf44d794aa0ee8ec0b08f' 
  AND token = 'cCp2NkeJHr2ZbBjDPq8Kd2z8/b5GRlbqnF9wVirlSnE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00044

JSON explain

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