SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '80e85411f5e9e16585a406a02f6e8160c2e4af63745aeda7ffe00ae25bfcf00e' 
  AND token = '7VVGeyxbOiEAKVnsDM/hQpu3sxCSXxDsy5frkwSq4gQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00009

JSON explain

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