SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5fb7f7b978ed0a0392d119bf44f2dec446d2280300730ee01f6dff923e26d8fd' 
  AND token = 'ZGj9f34JwlW0Zso2VLBWSIl2vicqtWRn0phm8iJAeeA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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