SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '43dd595f4ad7ae80081625dd379938155c5eb94614ef46d960a998bf5df63a32' 
  AND token = 'QnqeHm0ewbOLJLCHe2tf3vWmVrdeKJOckHDrEK8kA8U=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00039

JSON explain

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