SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '20a0732df6a9c5a614d7c434d24eccba76fc3699da338680418d1711cd88d348' 
  AND token = 'AW+PmgtG3g64L3gLlgXT97AIl4kNadK4a3KXeLgTdDs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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