SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '193b236137bdfad40d429a743cfcfbdafe320db22287cf4f218d815aab171358' 
  AND token = 'UaOwXDxef7i8f4rlIP8mJ01KY6r4IHNM0vcRk35e5cw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00064

JSON explain

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