SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'da055713f1e9d8e82ba15f07874419e7a555257f8d15e5109e73692aa9eed849' 
  AND token = 'YaKUZbfbyJwWaXBaduFOc33q7tnhHFgd4dNvKPHDTZo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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