SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = '58b1d4a952e88e3f46044c21fe990b719b18316a37e3ad615dd430e365563f6a' 
  AND token = 't0GN41hpfsYd4t+/4dNgR6/k8jazZUiwJQ0+qH32/G8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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