SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd68d95b38cc7d93dccaf5de26144c5273bc06d118ad5633b1244e8833efa8ff8' 
  AND token = 'uf7zW+sQs9WMY8gYMjYV09NboR8jHNBZ2CySvwUr7eU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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