SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2326cca77212fb25d96b752cb79900d2bb4de1e45d5ea5f458633b1b54e75c9e' 
  AND token = 'LhEUZUVlZ2vD1PRvTj5nVtBJsJFe1I8GzGGuMz4GxI4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00049

JSON explain

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