SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '081a1833eef213611b7231d85f62bca09ae3a51fb7855ae90566de2ebb32bb13' 
  AND token = 'NEJOsBBhuNMh4ipeBRgIs1UEw/yyhiAYZOydmjvRnfU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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