SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '846385005eed6730e9dffcf7641a6e74807fd522f293780952b4e1d3e49156ce' 
  AND token = 'kf3UJnjZdJOiV1+gMLFPSGVRaVnW/NSPyrYyl1z1dlg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00047

JSON explain

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