SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '69a0c975aac5e885e7872d2414979862f7d79daa3e11a6a8b82d007bb2665203' 
  AND token = 'mtvHL4G4BhXZWVXGCETVDONZzzxrUpAlWeQkA7gx3gE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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