SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3c6222175da7f32d03664a2e2f4cff4267313d9fcb7d2931cdd16f37a72a49a6' 
  AND token = 'SQmkjrLE6V6CJhLz46ZSttBQZBxxVHdZtbthKhbultE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00044

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}