SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '82d4c42e524bb6162c2a8f4c0aff4dc7bb985f35aa712611e24e8dd315b98cc9' 
  AND token = 'kZy/IPwBqpG/mIjgUoFGZ78IjrgrsPWM2HgLMEn2SDw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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