SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '82d2d3a3f5bebfc6d061dddacddb8595f29350f7f5fdb1b20f6e244fed41177a' 
  AND token = 'VkuCSZYvAwddELx+yE3Q8ryyQkoccQNmEbDlkrLm9ow=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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