SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '162e8dcffe91bb5a0a2c54fb4deeccecdc250e290ac00093db9230121ddbb300' 
  AND token = 'xklQ2IKHy5HJVg0izjrZyBlFGYyj9OGGcnzDYIUfNqo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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