SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'baedd2ec638c63e30fe3e4758bbd246bd6d8d5883b69ba9f10214e2995e4933b' 
  AND token = 'cBkiwprs/MfFkp1eawQowuG9eyWVLWN+Gj2IWMvMZpg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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