Sandbox

SELECT 
  1 
FROM 
  cscart_multi_declock_keys 
WHERE 
  key_id = 'b35260e42f6e64cc10564f2f3c8cc62a7f57ca97d16bd0c70e11bcdc1afe9da3' 
  AND token = 'pPiqpsHbGLAvs11ZV+MLdIl4Xl48uB3le9OVXxAunKw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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