SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0c37b72d5fbea544cb5287f76e36f954dab0ba58480ced3f81660931414d7c20' 
  AND token = 'QD7S8qO14mVaPQGkL5nF/HB9zidnDp+pWPk2ZDKFVmU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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