SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e336c86c4afcfcdc9310a3c756488ac89fa71c437206dbb0fe3774a267fb3409' 
  AND token = 'qiBQ5B2TQGdl8HY0VYzmE3Fqu5e5Bj+8FAotgkITAX0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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