SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '04e06ec7338c2f7232b3dcb465814dc468e9659cb882f10529a9cabdf90dcb4d' 
  AND token = 'mrZWal8oHwufm7r09Ae0XZDeKwQJCUHybewg+7mgNHA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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