SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8326e166134261cb7ac6f5158b38b76db1bae87a72650b4b07a4b3a8bbbcfbb9' 
  AND token = 'lRyS8kOyj+BN52KA8xqEBM/J3Z1WMGuTve5ArpevuSU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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