SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'fd9ce42e62cb20c85c35952265e8d8c9da33061f855ce2347ced11c956554662' 
  AND token = 'WAUklTkOFro7PZ5DahujEcTNgfPHAEhqH6nXMJTeuM8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}