SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'eae2f3d0f85ab9b47ed6533bc70629de8e9aabf0b75bd7247d350faea8743298' 
  AND token = 'ubsfHhWLfaiHrJ6puIrjtfj3DaDEaW/NT3FKd8XeD68=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00042

JSON explain

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