SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '93fe796d19504dd7bda3ec298daf8a5c9b5ba81675f5ee7fb3259d3c322d7f63' 
  AND token = 'vJePCzTLvhUwH8U18OrtjDk65V4nGDT7EhUUPgfJqy8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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