SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4910fb25c9f588cb07ec92497e7a6ee4fadc53aa9ac60a3464f553e443bfb030' 
  AND token = 'tK5n4yGa7izWKu4fGifxuafk0YhKk+5ZcJYYJVfAe38=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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