SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7c45d4a7b86b91e39db79a92fec9d372417683305dee6026521dfdfa64624feb' 
  AND token = 'rdsSw7FdKvNFsrOJCWNkgSzasOzr4cJZ4JPUDSQbpoE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00049

JSON explain

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