SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5299e0a2fdf751b3266ba205d54c7863d63f29359ad994946b84f5eb6c6d1c70' 
  AND token = '7sQDZSgqGVW+YYfs8K7JLwMqZZdQqu+2Q32mj5us3tA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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