SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2d491c98e0954820839fa885995761a66beb634d1c122f94d6745f05868b39a7' 
  AND token = 'aWYOqlwSAe6gQTo2zu2L/F51nQhs/ovizZ/bBTeiq2Y=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00035

JSON explain

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