SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5ddeaa848983fbbff1fdd73a1b75048177b5b180bac8582ece5aad0f7036a8d9' 
  AND token = 'FecNp2YWM0k3leWW9MVAAuXZMdIgOJZ6tEIbMZNg5JU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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