SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '515125f66e088f2f9eab5df4b1ece1656b7bd686a8c64af7289c9678d9dccfc6' 
  AND token = 'imWQqxYVv5vpCN8WLdnAoKYbg8djD51wMvuc23V7PMc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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