SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'cc4e3ec63ed4daa4a354944f1e1a846b93b623a34193f34bbb8219da9847cda2' 
  AND token = '3cfYhIEGIqFmO2K29QwGv0JxFrQrVKBN88MhLqGuZXg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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