SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = '09d12ac143a8fafdc2f323716b280de94ea4a9c911d1bfadcfc5f87e1e2609fa' 
  AND token = 'mpMHsNLFt+PQwe8eTiIE+/RzGrQLWvzJBl+jrOAMaZQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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