SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3b76efaf2c855462e807cb36ae5f7ea04af0c55a9b1a65d7ea65a9f97f4de73f' 
  AND token = 'vBLVjGeYzuMazTZnpS8Lhn8JvTKPrp7oOF4abuqd5jY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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