SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '701ecf24371de34929faca14bb796259248c1c90ea7543b95c10a68f0dc104d4' 
  AND token = '1hpKAwqpnLHODvLqIEWzkgsYdPCXgBXDaBIn7MnHMIY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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