SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ae928b3b59964d1cd0e0352ce58db47fff6751dd81569350b079010e54a4be45' 
  AND token = 'UpeNXDIGOo21ZEwH2FrpnLCw/+AR+ptVJw8SwZYvBYw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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