SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '31f7ca62b9ece10c8511caca32de5f5038e85eb4d069de9ad32039bb6eeb68e0' 
  AND token = 'qjsILWt/wwf6sve/ktwFXgZdimi9aqJODwOB9OGFs+4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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