SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c93684c5b7a8c58002933dd1ce539be5c3443c789639b958a2d56adbbe01e35a' 
  AND token = 'DaX2ozDP4/yHkgLcsvqT+MJdGUyTS2uWeCUiirAIO/I=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00037

JSON explain

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