SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e2ce79ef2294924f60e8115139de466bdb87f59fa9dcfbb6d6cfc59076a514df' 
  AND token = 'slvdIERLd0i7xMd17DGNrGSr9mgWoP0bq7r843BagMw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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