SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '723609ef5ae568c3bb4fa2add8d39c6ff296df1378b67581f027a5d685e69682' 
  AND token = 'Zy1v+SbYbyWIRo2fdjz7ttyw25l4/wnVyezf30cks2s=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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