SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a8999e94a3c977be88d21adac7278ff7b0873c32737ee4c29e1c3b8b95af160a' 
  AND token = 'GY0MoXVuiCZB1fMoUIxGG2AUht9XTJG8DbYlyqz8x84=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00037

JSON explain

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