SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '450bf05222853538dc443a441ad879159d7f037a85d7548b15a0a326bd8bfbcc' 
  AND token = 'H+loVjcHL5oElobYaqcCshM6lRJc95H9DixkvZo9UWs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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