SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c57af0fd0abe013d15c38e3121354e8afaec40fdcfd36191cb38bd4dcbb3f585' 
  AND token = 'ByC9s0CR4Ajv9laAqU8tinBl0AiDJeYkxlTXlhfXgcU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00015

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}