SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '13aeda5a87d4838814990d083df65057b5c7cef1f2e42158f5cdd83b9d670a38' 
  AND token = 'lGd+BtDQSfWZ1SMmECftNkbvFGl+gPe8IzkeDZGrVAk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

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