SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c77aa52c6ece3b090b3815bd61d9d77ab17b9cae5ffc4dd7e7a927aadad51b46' 
  AND token = 'kIZLWIYvYod4N3UwgaIOKFhMaNoObc+ocpBFW0idTRY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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