SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '29e8b099dbdcf360c1d7ce6d032a69b9e68e49e56a4be40992e1f1eb67f6d37e' 
  AND token = 'xpqhwzb3xCxwN0MsvnUvgk45GjEjc+NwbA8WvQZRstg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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