SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4f7fadedfe348176ec603fa91c30045c8eacb05ca7fa830d2004a67dce9733de' 
  AND token = 'AsOMkR91nGgFendLAq4wxCp4JoJ66RXtOU5dfncjdXY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00043

JSON explain

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