SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'cceccebdd7a2373575c9bacb551552777a1c82c5a558b2427de040e53373bd04' 
  AND token = '7BGOWzLaXe7pHpVivkoE84ApQUXeqJVCDapOfEFliuc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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