SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9277b98c86eb5ec31db9641ffe1eac9a2542221bd7c971813f9e40a90701de19' 
  AND token = 'hYgQgjjfR59+VDXzNh0qFooxoFuN4naxpFcEpRLSrPU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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