SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '6859fda7ef0f97d7babfacaf8d7ccc25437619795bdd80dd92a3143366014cec' 
  AND token = 'WciyurOlmiEnhvaFddFr30iDVomFwtr9Vi4UVsTnzCc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00037

JSON explain

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