SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c3d6ee630551136a54aeabf9a24dca359e797b20a510ab581b22e1b961318a74' 
  AND token = 'IBBBQi55yRd/utwIbWy5VkEH04JjcjUfanQK/JEu8n4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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