SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9cd6a1077b48e6069854d5d21780e51f578fabbf4fc8db77b16f9d45083ac172' 
  AND token = 'ZmmS5CXV5FfuW9OB/gIjWQsJje0dqkXfNhSO7Yc5hzo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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