SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2a08d427aa18d511fa00a5141cdde657e3297c2924d1e16e0e68b415e71d2834' 
  AND token = '184zWk/PyBZBbwsTGfBrKVlssVY7b9Y4+WBZkuPjTnU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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