SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ff59cb1efb0fe98a9d4ce1610ae07f807995f2a2cf7e413e4b947fb89e88387c' 
  AND token = 'mwyams7X7gr7abuMOqgqj+LwM+xt2O+XjPaXkZI9e2U=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00043

JSON explain

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