SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ffdc48ff8f3c783e33022a5199861ba86ae165551ad0f1af07f9dee33352da35' 
  AND token = 'IMZI8JdbLTbOY5+uTX9QOWapkI3HYycnVony1uZkwxc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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