SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '60193fc65971948084ee2e73a4a4bc43f645da5d91b346cb590e2fb9e98d06f4' 
  AND token = 'U/ANklrf3Sd8L/iw3sJXTWudgeBQb/RdSyDB+nSqzy8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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