SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8c2d403485a58cbc70fdb102202caaf65d3bfd78a18cdc6417287354e96aff79' 
  AND token = 'EG+xSt/Jzhidhtyl04pwf/hZ9nQqNbWw8fyEPmhhuNs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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