SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '753dcafaeb1ccd08fa859ff20247d7862281fc8ef9dd18b27fb62fe22325cb41' 
  AND token = 'Mnkd17Y7qNYU+wCMTB5wNPbJVZwvi2gCsrPeDwoVI3o=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00016

JSON explain

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