SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '036cda9be82157e1e9956f4f574cc6ba843e1c6ddb0285d327bb13618f8506ab' 
  AND token = 'u9NKO9/Bnm041DwNQf1EGNxpBvxvglmm7JeodEzIDVQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00044

JSON explain

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