SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3606cc49aa7242d325b89d2606e90e4568cdc85ae12aebbd091f86c05b3e9323' 
  AND token = 'EK+ZCDWXGMd/jCvVAG2zLotqTC6x90BJ/VqYxCZQolI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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