SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8d5ee3dfd4c74f468fa3b3eaebf1ff19bc9811424408e01afe9a9bdadbebd50c' 
  AND token = 'D190gF9Pn54uoLkFH2OeNFjZCwvywTlGCld+bXB7X6Y=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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