SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9e912cee2f3d856c730c244f5bf298a30788113d777739bbe0a58c46d5010b7b' 
  AND token = 'NZ6OhcBvooa8TjsgzqiiBbLFIYV6Hnt3IFdHBmc3t4w=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00044

JSON explain

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