SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '77a44364f75ff1f8ed330c9fee7efb4eb6f59faa024850d5b07c787aa61944ed' 
  AND token = 'DKhzaS+wYXvdW/oAmnuPyHCCotYEENcvxMsRiLS2b/U=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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