SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e18d33b3b7754d88aac75712a41f7a7ca1331cb01d89e26d743a5e9ef4c69367' 
  AND token = 'xow0PUol528PnT0sjnmg7shu3CGwiaWfwPnsyJcLaHI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00043

JSON explain

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