SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2f108dce922480771f8dbfc5d8f852c837cbb6a956a3e739c9c27e3556d79a5d' 
  AND token = '27kqU6CqfhH6hXTQDyrGEQXAKXBc5t9rba28lVzHxbI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

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