SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '096c29a54fedc3423df19f46804f1e7c6adcdc18c8e1bca082fc71535fd456b5' 
  AND token = 'zJs+wDZuqkjomlxCHFKee6nexEew2mHN/BvSrSsSWZA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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