SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = '18f636caf9f55a78cc2ad483811056ca289d90b9c4856ca8dfe3231fe408e7ec' 
  AND token = 'x055zd8pdBLYWPjP2RQ79RWZRuyP1k3gAZAwQJunPJ8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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