SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f9b860051fc26b7f748118f6d2a0736cd5b089ed7c32c96b2d6410fb5d90d60c' 
  AND token = 'K0ZXBGmjxLM/UxYZuGtDuk79UEsCBCluprbz6hOnij8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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