SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b6f17c7547d89df66ccaa8ee87d63f75504b0bc1a8098a94ab7a6dbf8b4a518a' 
  AND token = 'sr0vz+TmyNCxtrnKnbPl1kuqgWYzoGIVhFUBBqDQJdM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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