SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '759d4c61ec43ac86381a0c710c4efcf2adfe1db71c0ae4ad585dfed4e4d592ec' 
  AND token = 'bj+20A30CVBO+i7VNTipw0pf5+WXjSOOnTG1Q2yqQ6M=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00012

JSON explain

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