SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '453750f6ad39badacf5691170beb8dad4d6339caf30e01e4d5696f4e734d0b0d' 
  AND token = 'domqQIs0cGisDGh9AfZxjdamxe25ZGMGD9cZJkbarw0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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