SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '569a2bc6a94475787177dbd47ad33de74af08cdbcb2625f307f74c86bfaf2fae' 
  AND token = 'hjT0UmfH2j5TqKZEPfVl2TTR/YJ1ZHsOYPrO81D1wxU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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