SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f35559dcdfc7c3ac9e394e11aa49faeb2701c5939bd2bea205303830095406c2' 
  AND token = '2TfR+DKmqe+8EpVYbWsXd2nn8J//EVBCBVfvNUAk2Rg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00042

JSON explain

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