SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '267db9fd6dfc8213491b8af465141bda6cbf632e85c2fa7a35e77ed648d5c782' 
  AND token = 'CYiXJBdS63qv3bhtCgsktcD9oJF9Pe/W1w9zUjfSezo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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