SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '027a8e1a71d5c84f90642d4815ab20c4cce3da6aa81d238eb4f4f7ed4b5bec93' 
  AND token = 'GbAKZouoocHOzHImIfWaiqsJc5Y2QBU9IQKQDwJGJz4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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