SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a7ee675f97c48d7d11eb543fb04b05eeb600af99681f8765e5f0c8b0cb23a743' 
  AND token = 'ETPJIKU2oi5XVdxUZ2pJKB/vHFcPWQil5+ZrZtanZV4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00053

JSON explain

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