SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '948004af571053d1dbe573d76a14f555bd658b4c124dce1d59dec13078753114' 
  AND token = 'ToBms3DIkUgtNbBW4sjKXXCKzppSsT1VS9I0kDZYO0E=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00323

JSON explain

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