SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a176420c6381f50c71247dbad79466178f34cff6ba886081fc0672960054d141' 
  AND token = 'Eaaj4LhwyY7+goqS5LlXHihHzHl+/4T3o9HvVa6uczY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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