SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '9ac0777705ee199bee8353e0abdfe6f8acb6da6ae7d411db3db0cbe32f8546a5' 
  AND token = 'l7dHhkVdbJNu4VKvlEro1HxP98rqzJyVXxyyXpuiE3U=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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