SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0783eaeb1b61b2cdbb05f84086d26a21eb0651083b31d8e56b7e99db22161657' 
  AND token = '+QWYijJhCgSwOhXeZ4bpve1mOpbuG8lRdrLmt2h5dIg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00015

JSON explain

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