Sandbox

SELECT 
  1 
FROM 
  cscart_multi_declock_keys 
WHERE 
  key_id = '52d4d17f84542da95b6a6362d9da1c3c869398e8ea7da5dd67c32c1a11ae8afa' 
  AND token = 'aOw38+50lE0tWsrRrHoiaEoiqj6cOExcQs0CCLdeTvA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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