SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e82730cb9192c4de0a2cba5369c0033c48f94605dd6d3727d9f6271eab934e8d' 
  AND token = 'jTQQS2KZ1GzrfCBg/WbCOK2GROiFUIrI+9MSl8rYUw8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00035

JSON explain

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