SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = '4fea45b30f7d833fca2e1d91e062982c51846a28aa09a10f8526d1ebf32e66a6' 
  AND token = 'pjVqVQzXDubWExJ5tEDPeQrZimjDq2iKZKuD+XaKd6o=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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