SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0428391c80ed723f3d561e4ebc249c070e1427b782ac36a98a6e8ad5b4f3baa9' 
  AND token = 'lpW4oNo3+C51DCiAJ5+J/haKXHGg7v+UEArxEBvgjKk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

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