SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '44cbffe77d59a44aee0ada003c71d6074ee53bf0f784b260f95bfff4064ff7b9' 
  AND token = 'PrJd973Pr9JeuhfHzotRMHbr9pccEcz98uEARfrBO+o=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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