SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a541b26ecca91b054a3a1b1c86c77e8c110f96a6f09fa200b9905241cb78fe15' 
  AND token = 'K7fVEHqsFdYynYrst85nSDZX4K4FDF4tQHvbO8LkaOU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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