SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e1d344539535ef38e73e588f24b0b45bd8d0f9a009d381ca9be76e8a5e51ec42' 
  AND token = '7W70NRvp2MJBjrhhZZz+m8xd/YgqtATAg9LS+jc+Tgk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00042

JSON explain

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