SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8e0b1d645569f4503ed197daeea9d9222333f26d713ee7d83bee1482f6d405e9' 
  AND token = 'TMk9CTlF8uK3jRcvqlv4i0wL9HR+SHZJbLnUNjnNhOo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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