SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '226c023cd9006c3c5d03c29b17551f34f1669a6a2e8036907c8cbd2a6ce68e1d' 
  AND token = 'c1RvxQZLuAqfjrnL3ykNPlkmJij4xfMWh+UWIg8mt68=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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