SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '82bb5d4f2f3da29c991e1627007fc963e5549d3c751ae33acb091682be506e99' 
  AND token = 'YJz35Bwfs5jX6gYFWJmcPaQOhYhO+pJaYzxpWQE8Ngw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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