SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '12cee156837d05fb7fdc352fc05f989bea4d652a0812ec62aff1269a0fa95526' 
  AND token = '3U8/qCbTCUQ4oFm5ie8W9Mk9NQ8T4BVggyEgKwK+nRQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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