SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'cd8ea807a0dc45d3db213efec0cccca6a7edf0fc60a3d738118058f39bf2d226' 
  AND token = 'IqctJRC/MEuESeztesJ42Qj+h9rn8JzmfQ1k0gaiRug=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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