SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '479265988ed23d1115f5fc0456cc4d2fffbc5a494b3abf1050df3f61870a442f' 
  AND token = 'eyHjMPYoVquvwVvnqrndtjhVacsqlK0O4quYpBrcXf8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00037

JSON explain

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