SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1678970391aee64f17562934083a6c9e414218a5bde362cffb868a5bbbebf91d' 
  AND token = 'beewemoj/PmpXCQoU9pj//2+f7eADkJRdM+2B51pVek=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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