SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2fe7a0835f086a47f718e2b1ccd9f4fb28289d9c5751c632ddb885ed051c6f74' 
  AND token = 'v13jNDuo8MCTMfb+tQgXpY/xynDAT6tPCRhJdUjg0TU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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