SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '327b31b758e4a06d90dc95324e53a87b7fd2bae9fd2df4a907279c5ddb9420da' 
  AND token = 'lGwkfCIh7/Qfw2pdyi5GDleDjqQXIfnoXMlnvu3nWWE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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