SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4b22339dfba0381d2e502d79961603821c88a9d3267866c758fb4c29a96f30f1' 
  AND token = 'jokntZHfq9HlNQ8LcHskOuBTjLBqBkeIAwemioDK5oM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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