SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '61dfadf0ddc87709e5f43f0244a4123bbad98bb31db60b10371b398d4b49b889' 
  AND token = 'bqr5qBlKhFUKZYrodVI9SzU9NvGjZdaXReTHX+hAVxU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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