SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b08118eddb55ad044fd236c78f8bc52b5b842979dcbe012bbd27ed1a82cc171e' 
  AND token = 'TVN3ipHgPdiNVyKf0qS7LkKOcPpaE0j1zVtaX6OdQ3Y=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00039

JSON explain

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