SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8bfb738c549a9489ffc1a7f3cdc82d2a06dd81bc8389be97c0d59a1b36506252' 
  AND token = 'YNFbPAKt5ZRW5XESWrtEQKdxu2l3bHPxWXzD0BKV7zg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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