SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'adb0e672700173a1560d90b41bd9be70fd2fdb3d729ffead1e1afb7f634f930e' 
  AND token = 'sdUDe+NqNReyokOPQHpXDQ6MBIGiABpmF4KXT8IgrEs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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