SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8b9184a1dbe7fb4ce57a4e5250cbeef501084917e2f4da070b570bea3fb36e96' 
  AND token = 'kxgkICgT9dZ0yy5OEqpzfa9Htv7QnN8uWnGDfIuA56s=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00041

JSON explain

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