SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5dcfbe2e015d10898f97a1361a8db0dcb3ed1f19d70093decdef9310baeceaed' 
  AND token = 'WHESYoONEXP42Mbi3TkUHLKKh/c8Aq3C6Sntr0vHl+s=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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