SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '14c3479d65dd68de52015c922a757cf745d1d12be97947f4b7a5ecd359c58d63' 
  AND token = 'gvImTxwGbiFL4fBGda7vtAhECD7CJsFbVKSQP6OlC/Q=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00040

JSON explain

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