SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '38b7a5c7fc5bd2008eb14739924576da83ebdf414392be7b3b5c7181353694a6' 
  AND token = 'nmYmqgG/xzjLu+T9yKcRk5r6SKrgpd9Ilz4Ug5TEwP0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00045

JSON explain

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