SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '16fbfbb8bcf27b94bd3bbf7293fbdf6f586f1b4f290ff56d79d66171259aeb3a' 
  AND token = 'qvajKZTy8sqODM47wcpFOtPnB8fLMEeqJQFZ9D/FEcY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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