SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '13b1b4f2c3a708a92f47475d516d469f2a365612a995c390219183e27260697f' 
  AND token = 'Xe5uNTL7ndmRIYc7pkVAwaBXyM5GpSyV9/jR48wXONo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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