SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '320ef03bbf1ca5e3c78ca5e9fa65f92815cef35906e6c38ab9915b93f671580d' 
  AND token = 'L/9iWkreA+dI38RsSmc9jrZ+5R645DbbC0ucIfRXZds=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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