SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '98862af84352bcca10dcaf9f762bcca41ff967aa37cbd9067796d6e7a69712e2' 
  AND token = 'U89CqRkc3AcnzBr46K7jX5lHupItgNfuIXG/X8kuq1o=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00037

JSON explain

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