SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2d2cd29aab6868bb5d570ed7ed28f7bec05d8dfd7f9ecd2c1f542fe949712811' 
  AND token = 'IGr8jBR9yxWZZhqsjzkW6gmBjVsIVR+ZLbwmYyOiUIU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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