SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '6c33482afb9de96ad001ab5c053f9b14110bc1262f644e2a204f2dbc0d76d603' 
  AND token = 'wQRFGHJzPveowEYt38zO5Oy+9TRKCh1HfLHuKPVdlMs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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