SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ad680d7618a964ee3172d5f54344337ea8ffdaf692ae76038f3fea7f897048dc' 
  AND token = 'Wm+z6BHRv1hXymWCLQFiY/Gkiet5YggZjLReXFClQAo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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