SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '934c3e3d41f879c2ad671a83a23420c263f54013c2b7af05652de26dfeeb3622' 
  AND token = 'Cfuneo++Ft0sbl99Ip3m5xPBVEZKWDSuHaA1mUIGWn8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

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