SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '85050fd83bd0036cdd89b6ea9eeac8e6ca9504b2dee4a53f140c04d2ecff82a1' 
  AND token = 'QNxGk+OCnQcKhRA09iMvd7kNbrsrE55kv73IW5BbrkA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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