SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a08b0a931393fb28d876ac6a988925b5bbece405f937934b9c9ba0501bd87d27' 
  AND token = 'iM/Xf7ngOzegDpQFFP88py+TMfmGRovEOrygiptJb/E=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00039

JSON explain

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