SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a45d57da6f65621876d3ac00e51822e4c84a07d156b88b9675bdaf5c09ffe166' 
  AND token = 'RSnPSvWPmi59WbUDupkX+xHHkuhJIDlY8k4evPEjUUE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00040

JSON explain

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