SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '6273df86801ae0c31733553a103ed0f93b12ffc29f9c952f3ce367673d4d6a65' 
  AND token = 'aaTdvpNYrF71pFcJChYJ/6gxDaFnHCaSm01T7AEHtdI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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