SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd4438b5c0b52c82f41ea5a09a116ce6a426f3315cb5c271988d0f7741fbc6e9b' 
  AND token = 'TgaonB4VqfcmlljCF/VKN8EB6rXCjScXaCqLSw/ClDg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00043

JSON explain

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