SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ef93ffe1c5fdce1007fd69604f7069bc80216cdf61bb11329da3f23f692cb283' 
  AND token = 'IySOs1alh/ceANKhy68H73Kc7/IPmPcAVbQLGr3hVIo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00046

JSON explain

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