SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd0a240f42f487657593e011f624f7956470eda27512983879f9cad49f89b9b7f' 
  AND token = 'gh6lfhA3340eQ3gpyL454VElMKTj7S+cpIwN5/em/n0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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