SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '116c99f48866410061128a97a5ee3ddcaa58cbbf38e3cbc280833fe6c06afd11' 
  AND token = 'uxBjQHZEzYX/RYT6oUpqX8fLNDvNLI5HEhPXI0XUsSM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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