SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'bbe64301045760ca940bf437e7dc2901b41459684ea98d9799aea6500775efd8' 
  AND token = 'Jg9BgQuYvSnY9eyfktY1AzKgI+MZzNK5tJzzNj6Tn6c=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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