SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '128823b26de67289ef4ffa0256355fec988db0c7d665c81b33f38ed0d35ceadf' 
  AND token = 'DxBMvvV7EwNoJNP9ZOvfCp4VrxtX6rzuqOJd0Hq4L8A=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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