SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '49976846b21b13fbdc5eec97506784670b8dca6ff7ccc9a28e544358e491b68f' 
  AND token = 'xDQ96PHS2ZkuRtP09iiD099kEiZ7S2rjePQX5VOo/lk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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