SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5505510fa814ad0ae497e4bda554c44c1c5590544abe2ab4b24a5c6b274a3ffb' 
  AND token = 'K8DWx1LaRDb5UMA/oVqQ2ZwI/XZoyuILZ45lsr8mIEg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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