SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '43f6121c65a76916dc126f037f7f851eea125e56f2ccb72e4503076e8383e9a6' 
  AND token = 'Wq2WmW/+rVMcPwdUqoePJsuI9R0OG1njKfd43VkR9I0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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