SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '25f982c38a20f7f3258ed887fa09de4b694d00be596d9987a5764878a94dd681' 
  AND token = 'QgUhOvkz3x4CwcaiheJJGHg7XpQFjnAzPYwrh3ithEw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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