Sandbox

SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7c9f9b83be6dbb524ed1cc9511382327887e07a4fa29eb5f87cee33682f1626c' 
  AND token = 'vf9/uV7uhqFMxsmhvF67mJxuRM4nwoshynGcfq2UDwA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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