SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'bef810438e343e67c187d692aca0b5bdc08daec360cfc9fcd27fd6e6f413d4bc' 
  AND token = 'FpLFqdOdS0zK86aUZ+JlAfICmGUzlqL+UAvVwn5BJRo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00043

JSON explain

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