SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '24f92775699aa6cfa38bb70b3e5fdef3ae8660f2b98b1ea57cceb9d4dcb4ca48' 
  AND token = 'gonoIjOHw/oaTiL4ebcQGwWevH547Ze6uKBqz7jBt7s=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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