SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ed315b5b8325833a0cc56726f876a9b6a665e81bec846c25dff4da13a60bf8d2' 
  AND token = 'wPBDKKoheO449cbEgbVOOvsqyTQdijUZsVaPdWRD/gI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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