SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd2132ca64b6d29059c43a285ef34e36b606cef44ca7f908235b1a4173f764d8c' 
  AND token = 'wRVfZSPdafVYhTrM8pvCcgM+uiAsrRqaoGXajtl1tY0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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