SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1181471f25a6c051558522fd71d40b8c38814f8bc235dcb1a751b7d8058dcf91' 
  AND token = 'vFplCAhn35XJf5o1GchyqOGW8jOe9cRlAOIaVwPmtN4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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