SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a3615dde599eed135e86b5375686cbe453f9d9a5bf191a9766b279645b84b1b1' 
  AND token = 'wUanRAbYGn5jJqOzx5P6dEx7Gio6N9OwYB4wijvKfj4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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