SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2c192e39939fbe8d95cb56036465b979ff4c58e0e95256d9ebf80eed47db43dc' 
  AND token = 'Ae9xFGDqXzSCAfWqFhNW6bMqzqJNvzuXaNlVqWawiVs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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