SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ec88df7e2659b642d84fb5b53ee5fc54f116472e093ef95dceb5f15a39abbfc2' 
  AND token = '/s4KDMquwZA1v2iQpq11px5BLgkuyDoV01UZrwzXwV8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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