SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e5a548ba3f175b2351ec259120a8ba34dadeb717b2e35521bd99566742e1f64c' 
  AND token = 'k/DfOlJTvi1y6Pi1GqWnNQmhoue9Y8bSoCkQtI3vscY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00040

JSON explain

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