SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e957fdae79ed48326f26f787f1b11416d3522d4356153527f705149353f2ab66' 
  AND token = 'DeXYskgDesKittLaM4IlfJWEBED0g/QQWWMAh4csSTY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00057

JSON explain

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