SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'fe94a740264ac9534313bb1ff615d2adb71683cf33273a43c0784344d7d54bf9' 
  AND token = 'mMmAcxManJjonuEceYe65iCbKvQFrx/KyPGVtciJPzM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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