SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5a898403026c78eeee903ac1329dcacd927ef4508cf59184347d1e9581584221' 
  AND token = 'pJYTFhlO4YEC2FZuNJHXRAUiGGebbMnynqH4NEOOy5E=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}