SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd72a5bc58302869081c0b2b3861b426183847ebd18be5efb6142e386945c0d9d' 
  AND token = 'DwAv/EgoPjb6dyk7SyBV2D17ADJ5BZc+GOY3JiJVUXw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00065

JSON explain

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