SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '101525f349646c1873fba24710afa165ec7896ea9e03c55c24da205175fd321b' 
  AND token = 'hZAxT4XFJe63AA4ZWMS1hpj4Qa4CvnZvVNXMQNtkuQA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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