SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2e1a65f9dfea5058b5727b30419a0b4c63f4219fd4f79c87a3250fed1207fc88' 
  AND token = 'nmqfYMeiQA1fuhzPyCOJmmNUWEBhclwhF3OZmFuZS3w=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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