SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'bfd20339ad8a60f44329c6afeee0908979f8cd3759363bcb0617e2c04fd2dd3e' 
  AND token = 'KPaH6EWnsL6BmwHmLPm94wBYn6tBEt0R9kSjWxjKBKE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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