SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9647fd202cad033f54f85d2b72d530e2708e40eeccf28460daa85f2460ce708e' 
  AND token = 'mWKg0DFlbK7CN/1lDYfry8Gvzy2F8KwVNq0Z1F5OjJo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00051

JSON explain

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