SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '043fd630b380a1cb36801fe87ee416701da8109102d9459b9c61a53863ac2fee' 
  AND token = '2lEewSKD2YNkattgMLWlIwgg87SDUFH7lAwKlqCX+w0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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