SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f31c377aca15211d6b0a26a20c66a7d6eb477846fc96329c1d4b3f5708e0da06' 
  AND token = 'PT7eNJ8B5CDwC/6rhmrYJCdZqd2soJj+CAYmpebJBzg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}