SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0dad268d420a20c632a1e78d82a4f9c699f24ef657f9e5b42a231c2482e61474' 
  AND token = 'j3SEGyA5T6tHHiMOio+AQY5q0oLdeiJmNkp8fb/NFlg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00056

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}