SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e6322b2013d309ca6f3fd0e44449b684ca617c71207f5ceea5f8ba0adbc5744b' 
  AND token = 'n/e+lpqk7KHsZez8t4Za/UwqBlm7DwB5ByLSwU1vtQY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

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