SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd5b3a192cbbeebb55e4e534cb06eb4bcdf31ac8cbd1ec0d73979913d622bf3b6' 
  AND token = 'shZh3CGc0F9BUaE5fdh1LbQy/UtDalXSSbUsfe4snNs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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