SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '42fd750c3f3458616a961613244e3fad0ef1937feca6a462a698c780d2bc92dc' 
  AND token = 'WvzicyqdHVte7pPLF3D7qSIBG6PsO0RQyPlf7hEOqMU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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