SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '313d656cd291a8c7ac4b139d82d5e056e00527e473f583972f5ca42b18d86ccd' 
  AND token = 'MnfnwkDwvKsSHaKIVKwjYd7Ju+FTYlvnrGFbDA78ZJo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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