SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '774fcfad165615a82417797dc01dbb0f44e93caabb98913f90745d1aafd2f87c' 
  AND token = 'KRw5yN1XkNnxW6wp9F5FqOodIe/wfb0FgVlIDPhO+Mo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00014

JSON explain

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