SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd1393231a90eb01475acde1a47dffd4ba9474c533aee9e82bfc836bb7316a0c0' 
  AND token = 'KXk6wMDgOkiOJnINThO9o67VRF9+7HMx5GlxkI8k7J4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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