SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'cbdc840b677d85f596549406f2fff888ea2494a12874763ec7df0de64e97dc12' 
  AND token = 'Sb2dBuPmglKDM5Ge7CuiUoKhyr3ZWpf+/jyluBKF26k=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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