SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e4f6882d6958338f8fc16c512c66d89287ade17b4bf4d465e9425b9b9beaa934' 
  AND token = '5DpUkrSfxD6JZMSB/vqZLk5Vr144QnuyxOeMtMsy+9U=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}