SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'bca7b45cb3ed0d006c89ac840a551f0c26d5f52f49579d2c9f2f01fc47b764db' 
  AND token = 'QZFwGCcEmLxkQKoHgv/0xMnOukKUZrvgOxpkyPcs7aU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00035

JSON explain

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