SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '99f50db873a9c49eeb65e01b67e2a2340755ebf103cf463e9052cba25ef9d838' 
  AND token = 'EnSyK9dtenaw5jtoZ+mvXI6gBPuW9N6shSFmjFaxT+A=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00069

JSON explain

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