SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '347b2336d8062549bbbaeea24fe0f23b81bed8c831cb11b01c0cdc7ba06de888' 
  AND token = 'WTaLyVYSJYm+9ayGjrPwZ7QBvv8qJi5BItyF92VwNTw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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