SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b1b64d8945aa9f3a159cba194a91c24463b581b4b1dce2f77121c187fafa8b89' 
  AND token = 'zNogtWk1T+BvwqKLLu6bJhtAywr7ZFw+/pw/LoKqHhM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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