SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b25bedc6a7e7f185fe168094ddd0d058fa7b685b8525de337519bebaf22cf449' 
  AND token = 'pVisdt4zNwonWtIFCqK6TQJWB0BacsiAJzwVtW8C7OQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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