SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd435a53211bef8052aba504d3a531496307c596bb99136bf0d07cfab1d89019a' 
  AND token = 'Et59NP4Pj5jKCyluDOIdl7femmFSzIY4uzR9+k+Mqdk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00050

JSON explain

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