SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '89c36d91846fb4449c45a6c2f455649f83cb0c75e29a5a7d7957056405d680c9' 
  AND token = 'OZCk4OrDvsPRKbOJAuObAIlulVoUOGZXpsaUVNavh6U=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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