SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '825d8600df9d2098281db504a53cb9341e99c065123f3ea2cd64288eaf9c36b7' 
  AND token = '9Zx5WY7YvEsyuN4BskijmkW43zCzuKeO6tG1+OoocXY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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