SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'dd26e0643a7cd85892c794e256f94b0f7e214dcd830fe2b95b42a79a50a2042a' 
  AND token = 'hQe3VLlEvj8SKfWgl7uXHpm+xlkZlMnQt61iOeYJXVY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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