SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'de459ed9d695e478ba7ee6be3f1bce2d480575424d6ced8a95b856ddebfafc72' 
  AND token = 'DdvqPSR25VhJlwP7df0aH07Ng1A+pCfOTL3Z50AJ3c8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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