SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '69f3b60406c9d15a28cbfeba1f4b3996e558be963a9c0bd154143a9fe18b5692' 
  AND token = 'HtbWbPsarHE6elGfxwYh6O6I1Yk9YFmpaZjKBGYTACE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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