SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '435febed00e3ac1ceacf9af59a7ca1f28496620099aeae9f0ab5929930ce3cc2' 
  AND token = 'EEP1xtYJEjzoGp96rwsmr1KvW0mFaD8Q1+lvidEBgUg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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