SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '36758e8ba4b682c5547a8272ddebc9c785eaa15464a0f9188457ee0aeb7378f0' 
  AND token = 'eQUZL/6Ne0d5dMCKobfbf+JbcDTbEJc7bNzmp7fb7bI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00045

JSON explain

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