SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a9446403787ca3a5b9208c1bed5287b4f7af1d20d50fdaa676fadf7d7b0fec70' 
  AND token = 'HT89FkO7PJxpCsQuL/Sub4QqoZhxjshzjQ4QZBr16Ow=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00037

JSON explain

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