SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '625dc58755b2c7314347143e99fed2d7b4b7631dd3e3301dc53b733e9defd335' 
  AND token = 'gu3mOrSwKGJjZYxnvhFF4KyxyNm8Ro/nv5U6HcGN01M=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00015

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}