SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b8830e62bb1d528be6271bae7276d59e965a7893ce6c88a1bd6c0ae64df8a696' 
  AND token = 'lrPAdqy5d8FYpVX9+9+67+LX3gubMJBbZmR3Bswg3sk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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