SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9bbd4ef434bc42e4270a086ebfbe02653db6156fa011d9340a283cdff6f71977' 
  AND token = 'CVwYC8ZLxBiB/jch74iVqgrJlj+vm03TZMnVXvJXC5c=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00051

JSON explain

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