SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7ce56993bdc002f734b74477a6ba2301238b7e4780f36b4c2125aa2502d61228' 
  AND token = 'RtsERoStPatHoVkEppWzJTcO2TUhZ9ESX/NAOVuxHvk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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