SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '958592aad0cae3d81806852b9a4632c04d81458958425870c88e63069af8d641' 
  AND token = 'QnkIqXN3MAUlE4DKt/kMrKOg1VThffxcOcU82uY8L7Y=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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